Like 80% of the top 10 most contributed libraries on github are either MIT, Apache, or BSD. I think you underestimate how many corpo folks do contribute or wholly support open source libraries.

I write code for a living. I cannot, by any means, utilize a GPL library to support the needs of our customers and will either have to write my own replacement or dig to find something with less restrictions like MIT.

On many occasions, we will find bugs or usage gaps or slowdowns that can get pushed back to the MIT licensed open source cause we were able to use it in the first place. If your goal is to make sure your library gets used and gets external contributors, I don’t see how GPL helps the situation as it limits what developers can even choose your library in the first place. If your goal is spreading the ideology that all software should be free, go keep banging your drum for GPL.