One thing any regular raider notices after a while is loot doesn't necessarily go to the most "deserving" person.
Some guilds gear up their main tanks first. Others may see this as favoritism toward warriors. Some guilds don't allow non cookie cutter builds (feral druids, shadow priests) first choice on non-set pieces, because they don't want to be unfair to the "pure" classes. Some guilds allow alts and guests the same chance at loot as the veteran players.
The last category is what bugs me most.
I think it would be hard to find a guild that is pushing progression, also allowing alts to win loot over the mains or guests who show up for one raid in a month over someone who has been there 4-6 days a week.
Gear and attendance are some very key ingredients to success. Those who attend most should have the best gear as a result.
But the randomness of rewards don't ensure this. Your class may go months without a shield dropping or a bow, etc.
So couple that with the issue of when it does drop, you can have someone not even in the guild win it. You can imagine how basically - sucky - that can be.
1 day ago