I think it's a very interesting sociological question, with some potentially interesting implications.

In practicality, it's similar to any medium where the amount of content exceeds a persons capacity to consume it. This is not exclusive to Android apps. For example:

• The Web and it's tens of pages
• Movies
• Books
• Songs (or artists for that matter)
• Computer Software (eg. linux software)
• Etc

In the end, we are happy if there's software available that we are looking for. The huge repository can be seen as a boon for selection, not something that has to be consumed fully to be enjoyed.

That said, I have a finite number of apps on my machine, and I'm ok with it. I am grateful, though, when there's a rich selection available when I'm looking for new functionality.