Surely there is a middle ground for contributions which you don't really care to retain ownership of? I don't sign CLAs for projects I want to form a long term contributor relationship with, but if I am just trying to fix a small bug that the (probably corporate) owners don't care to fix themselves, I'll sign that code away without hesitation.

FWIW CLAs do not sign away your ownership in code. It merely gives the project the right to use your code via a license

You know how you sign those end-user *license* agreements, which do not give you ownership in the code of those applications?

That's the same principle at work here. You are licensing certain rights in your work to another entity. Generally, the license is giving the right to, inter alia, reproduce and distribute your code in perpetuity.

Because 1) I work on an open source project as part of my employment, not for free on the side and 2) If there was no cla, most likely the source would not be open as the project wouldn't want external contributions. That's strictly worse. Also, the types of contributions that the project would ideally see are mostly from other companies, not people working in their free time, so the cla doesn't really discourage contribution.