exactly; in the emacs community, when somebody is chasing down a weird bug, they get asked to run emacs with the flags that disable all the startup customization as the very first thing, because 90% of the time, its a problem with some interaction in the user's (byzantine) ~/.emacs.d
The first thing I do when I encounter a problem in vim is to run it a) without plugins, b) without my .vimrc, and c) with neither plugins nor rc.