MMORPGs tend to use item rarity to encourage mindless grinding of MOBs as an in game activity. They do this by making the item very desirable so players want it so that they do the grind. Then the game developers try to set the rarity such that most players that are farming for the item get it just before they quit in frustration.
There are two reasons why game developers resort to this. The first is to keep people playing. If the game is subscription based this is easy to understand. If the game is funded by micro-transactions this is not very intuitive. But what happens here is that very often the game developers add something to increase the chance of getting what the player is farming for. Often these items boost the look chance or loot quality depending on how the loot system is designed and where it fits into the loot scheme. So keeping people playing boosts income.
The second reason why developers resort to this is because it is very simple to do. You add to the game a way to add MOBs that drop loot and that system allows individual items to have an individually assigned loot chance. Once this foundation is in place it is easy to add the item to existing MOBs or to add a new MOB/Loot combination. There really is no thinking involved and if there is an established guideline for how rare items should be the variable of what to set the chance to get the item has been defined in those guidelines. If a developer was assigned full time to add items like this and test them, it would be possible for that one developer to add a hundred or more of the items in a month. So occasionally assigning a developer to add an item would not be much effort. This would allow a smaller development team to increase profits.
Given the licensing agreement for SWGEmu based servers, maximizing profits is not a consideration since mandatory charges to play the game are prohibited. If anything the income side of the game must be driven through encouraging donations to keep the server running. So how things are done in the game would be influenced very strongly by how they increase enjoyment of the game and making the game so enjoyable that people want to donate to keep the server running and their having fun.
This causes a real problem with item rarity. While players may be willing to grind longer for items to make them feel that their past monthly subscription fees were justifiable, this is not true for micro-transaction and free games. Unfortunately for micro-transaction games this means that the items that you sell have to be so good that people often feel that the game has become a pay-to-win model. (Personally I only use that term when the only way you can get items is to pay real money to get them. Paying to make getting an item less frustrating I find deplorable but not truly Pay-to-win.) For truly free to playt games like SWGEmu this means that what was acceptable in subscription SWG for drop rates would not be acceptable on a SWGEmu server.
There is another problem though and that is making the drop rates way too high. I am not talking about the miscreants who like to jump in and disturb things by claiming that the change is to pander to those who want instant gratification. There is a big difference between removing frustration and improving fun by reducing a grind and handing things out by completely removing the grind. The miscreants simply want to stir up trouble.
The real problem is accidentally doing what the miscreants are afraid of, making getting things way too easy. If getting items in an MMORPG is too easy the MMORPG quickly looses the fun factor. It would be just as much fun as playing Blackjack with all cards face up and where you could see the next few cards to be dealt.
There is one feature of MMORPGs and SWG was one of these that makes it harder to determine when drop rates are too high or too low and that is the ability to hunt for the item AFK. If you want players to get an item after playing for a month there are two number that could do this. If you believe that people play ATK for three hours a day and seven days a week this is roughly 84 hours a month. If the MOB difficulty and spawn rate is such that you get to loot 20 times an hour you want to set the loot chance so that after 1680 they will have looted the item. A very straightforward situation until you consider AFK play. AFK play could allow players to get eight times the chances a day. So if you use the ATK number you will have AFK players getting 8 of the item in a month. Also if the MOB is uncommon you may have the AFK player reducing the chance for ATK players to get their 20 loot chances an hour.
SOE generally would cut the loot chances so that the AFK players would have the one a month odds and ATK players were simply very frustrated. It also developed in SWG a mindset that those that could AFK reliably should be allowed to do so and sell what they looted to the ATK players to make money. There was no need to try to allow ATK players to be anything other than frustrated by trying to get it for themselves. After all getting it themselves was bypassing the player driven economy.
This is why there are discussions in the past SWG forums and in the SWGEmu forums about there being too much AFK play or drop rates being too high on some items. Players are not stupid and at some level understands this.
The real question becomes how do you allow both AFK and ATK play and control item rarity so that things are fair?
What I would probably do with an SWGEmu server is the following. I would create a mission type that could be done that would generate a mission only MOB that could give players the 1680 loot chances a month. This would deal with the ATK play since I have not seen anybody be able to AFK 24x7 mission terminals using the in game AFK tools. For those that want to AFK grind I would place the item on a wild spawn and set the loot chance such that they would get the item once every 15,000 loot chances. This would provide both ATK and AFK players a path to the items that would result is getting about one a month. This would require a little more work but would not take any play style away from either type of player.
Personally I do not like AFK play, but it has become so expected by SWG players to be able to AFK that it is far less problematic to create ways to work around the problems that afk play causes than to remove the ability to play AFK.