Less Desirable Specs

I read a lot of things about how not to choose feral for druid, ret for paladin, enhancement for shaman etc. For instance feral dps druid does less dps than it's melee counterparts. Is the druid not always been a hybrid, meant to enhance other classes to make them better, not beat pure dps in the damage meter? Is it not desirable to have a feral druid in a melee group for the benefits of the other melee? Yes they do less dps as feral, but does the 3% to crit overall give the raid more dps? Are there other situations where a hybrid's ability to increase the raids dps/healing make up for not beating the damage/healing meters?
Also I am curious if guilds existed during Nost, that did try odd make ups for fun?
Also I am curious if guilds existed during Nost, that did try odd make ups for fun?