For many composers, for centuries apparently, part of the primal ritual of establishing a composerly identity has been an obligatory period of conflict with one's teacher(s). I was lucky in that I was spared that period of conflict. I got along with my teachers and they (mostly) got along with me and we even continue to get along pretty well. Now, some of my teachers — Lucier and Young, in particular — came out of their own obligatory periods of conflict with composerly identities employing an absolute minimum of means to achieve a particular maximum of musical quality. For their perspective, it is probably the case that my music tends to do too much or have too much, but thankfully they have been consistently gracious about it.
On the other hand, there are certainly a large number of musicians for whom my music appears pretty minimal. I just emailed a copy of a wind quintet to a friend in the Netherlands who got rather cross with me because the score, with plenty of notes, has no dynamics. There happens to be a reason for the absence — the piece is about something other than dynamics, so as long as the loudness or softness of the players doesn't get in the way of all the things that the piece actually is about, or better yet, brings out some of those things, it's really all the same to me — but for my friend, I was was being irresponsibly minimal. No matter that I had explained that I had really worked on the issue of the dynamics, that not including them was a serious, not a casual, decision, and that while I could have come up with some system or just written in some dynamics extemporaneously, that would have been, to my ear and mind and taste and temperament, essentially an arbitrary act. Never mind, I had violated his notions about the minimum contents of a respectable score.
People really get angry about these issues and while never quite getting angry, I have worried about them as well. (See this post about fat crayons and musical pidgins from 2005.) I suspect not a few experimentalists and complexists have had some envy for the ability of mainstream composers to sort of skip the issue entirely, riding along on the autopilot of conventional practice. If I have acquired any wisdom on the topic it's this: The problem is never too many or too few notes, it's having the right ones. My own druthers are for a lower limit, but the choice of a minimum of ways or means requires a certain amount of confidence in your choices. On the other hand, being more inclusive, more expansive, and/or more complicated can be a good way of covering up a lack of confidence, with a surfeit of apparent labor providing a tempting measure of cover for that lack. Neither approach is automatically going to be more likely to produce the right notes, so if someone starts to knock you for having too many or too few notes, just knock 'em right back with notice that quantity alone is an inadequate substitute for actually having some criteria.