Because not everyone judges their worth by the size of their aircraft?

Just a few reasons:
The E190 doesn't do red eyes. It's got decent movement due to people transitioning to the bus. A lot of guys are already typed on the plane, so they choose it to have an easier training experience. You're only seat locked for 2 years, after which you can do whatever you like.

It's a personal decision. Plenty of guys prefer it. There will be lots of E190 slots later this year.