That's a "hole intention" alright - you can't limit this question to something that simple-minded I'm afraid. A "performer's viewpoint" is hardly what determines whether copyrights are at the heart of this topic or not - they are, period.

Ever seen one of those "50,000 MIDI files on one CD for $25" on the web? They were scabbed off of the alt.binaries.music.midi newsgroup years ago when people used that forum for exchanging midi files. I happen to be very good at making midi files and I used to post a few now and then for others to use and enjoy... I was hopeful of even selling some of them someday... but this ripoff changed that. Once I checked and found out I couldn't copyright arrangements in the US, which is what my midi files are, I realized that my hard work would simply be resold by people who put no actual effort into the content and would likely sell my work for cheaper than I could.

Of course this is strictly from a MIDI file producer's point of view, which you may or may not share, but it does affect why you can't get MIDI files as easily as you may like as a performer: copyrights have their limitations and I can't afford a fleet of lawyers.