lots of reasons/opinions:
you may like it; others may have another opinion...
think it depends on the palette you are using & what mood you are trying to create with that palette
Also, many make quilts identical to the ones they see in magazines--and many use traditional WHITE
yellow is seen as a feminine color...
it's a great color--it just doesn't "FIT" with every project--
many of us are color challenged & i find it hard to build a quilt around a single color...