That sounds like an excuse for NIH. It's an easy one to make because there are so. many. bad. jquery. "plugins". But there are also excellent ones; for instance, it seems like a big waste of time to replace jQuery Cycle. Similarly, I'm 50/50 on implementing dynamic tables by hand and using DataTables, but it seems silly to say "never use DataTables".
It seems very unlikely that any truly useful jQuery plugins are lost from this though, it seems likely that any that are unrecoverable (or extremely difficult to recover) meet the description he is making.
I never used the "plugins" site; it was impossible to know which "plugins" were truly careful and well-designed libraries, and which were just extractions from some web designer's last portfolio site.
