Because i'd like my software to be useful to normal people.

Because AGPL implies many things not all developers want associated with their project?

Yes, due to their virality, GPL-flavored licenses tend to be the "top type" that you can just cast the top-level project to and call it a day, but try convincing your corporate boss to AGPL your money-making product. That's gonna go about as well as is predictable.

AGPL isn't even compatible with GPLv2, so you still have to worry about OSS license compatibility. So given that you have to worry anyway, you might as well pick a less obnoxious license.