Wondered the same about myself but if it makes you feel any better, I've finally stopped at north of 40 games

Several reasons for stopping - like chuckwurt I can't stand to have a machine not working
So ... when I finally got the Loft finished, it was the first time I had all of them set up at the same time
Day one there were 4 or 5 that did not work for various reasons. That was enough for me to embark on a new mission - stop collecting and start upgrading to the best example machine I could find. If I did not take that approach I would be forever fixing machines and not playing them - and I love to play. I play every day

The other reason is that I really appreciate the extra space I have around each game for when I need to work on them or add mods.

Long way of saying I thought I was in the same boat (probably was) but I'm "cured" now