Most arguments against feudalism seem to state that the problem of feudalism is that it wasn't the same everywhere. But as far as I know, there were many feudal-style societies with their own nuances in medieval Europe. Why can't we say feudalism to describe them? What terms should we use to refer to their systems of government?
You may be intrested in this past AMA featuring /u/idjet and /u/TheGreenReaper7 titled "Feudalism Didn't Exist" : The Social & Political World of Medieval Europe.
What historian did you find that was hostile to the term feudalism? I haven't heard this issue in any major historical text or from any author, but it does sound like something a sociologist or other non-historian would say.
Just to add some nuance to /u/idjet and his wonderful explanations of the reasons why historians are so hostile to the idea of a systematic feudalism, I wrote a short while ago about why not all historians think all feudalism is bad.