[Galadriel55]

Feanor did add quite a bit of brightness into Ea in general, not only to ME. Everyone has their own opinions, of course, but I agree with you that the Sil is an excellent book. He added contrast. Yes, he did cause a lot of evil, but that taught everyone else and now they can appreciate and love the good things better. Before Feanor, there wasn't really much to compare your life with. Feanor made the most beautiful creation ever, but he also brought the greatest sadness. By doing that, however, he indeed proved Eru's words "if you try and go against me you'll only make my creation better"
You never see some Mamma's darling boy as a great person/character, even if they do accomplish big achievements. Feanor did great things, even though they were not approved by many. After all, great does not necessarily mean good. It's this kind of people that are remembered - the people whodo something special, unsusual, unique (either good or bad things).

PS: I think the Mamma's darling boy Vanyar king's name is Ingwe.

Edit: deeds of such magnitude as Feanor's ones are great no matter what