The trick is learning how to separate the wheat and the chaff. Most of us could probably look through a stack of Wii games and instantly know which ones aren't even worth trying... while a random mom and her kid are going to go straight for shit they know (ie, movie and TV licenses) and get burned.
For well-informed people like us, yes, more is better.
On the flipside, for small game libraries, less can be exceptionally worse. For a system like the Jaguar or 32X or Virtual Boy, there are important genres of games that are entirely unrepresented (There's only 1 RPG between the three of them, and it's a crappy and rare one at that). People always mention the Dreamcast as having an excellent good-to-bad ratio, but even there, if you look at specific genres, you might only find 2 or 3 good games before the well runs dry. PS2, on the other hand, just keeps going and going.
--Zero
overall a large amount of games and developers should result in more good games but as others have said the DC while having a small library had tons of good games given that amount and likely could have had more
If its older systems it depends on what style of games you like , 100 different saturn games vs 100 n64 games is going to be radically different from each other cause of their libraries/markets. Like if you had a saturn collection its going to have more shooters , fighters and rpgs and n64 is going to have more fps , 3d platformers , maybe racing games? Is really depends on what the system focused on.
U GAIZ JUST DONT LIKE CHANGE , (builds a artificial foundation here)
I choose quality over quantity after several years. Only buy games I know I'll play over again