3 years ago my music teacher told me it was a bad idea so I stopped doing it, but lately I have been checking a lot of the best guitarists and I have noticed that probably half of them anchor their pinky when finger picking with fingers or with a pick, but when they start shredding they stop anchoring. So i started doing it, it felt comfortable when plucking with a pick. is it a good idea?
this is one of those.."what works for you" things...yes many guys do anchor..I do..my picking style and attack are far more accurate playing jazz and fusion type things..but even basic chord structures for me its is easier..and sometime for a certain feel I will use my fingers..

teachers may be good or not on recommending how you should approach this .. they guy I studied with did not use a pick at all..fingerstyle..but he knew how to use one..and he would anchor sometime .. he did not recommend one style over another..his approach was - how you play what I teach you is up to you..

play well