Is it because MIT/BSD software is more common in web or scripting language cultures, where code tends to be replaced faster? Or more common in newer code which most will not survive for years?
So with the BSD license somebody can take your work, improve it, distribute it under a proprietary license and supplant you in the market. Compare macOS or iOS installed base to FreeBSD.
But then the codebase is henceforth tied to that company. If Apple is dead in twenty years then probably nobody is still using the iOS kernel (and not because they switched back to FreeBSD), but if Google is dead in twenty years most likely Linux is still popular all over.
https://en.wikipedia.org/wiki/XNU
And Mach too is available under BSD-like terms.
Arguably one can just call it Mach, as the bsd server part was delivered as part of Mach.
- software written for a company has a lifetime ~ the life of a company
- MIT/BSD software may be adopted and not shared.
- GPL software would be shared widely and changes would be given back.
I'm just speculating and I have no idea what the real statistics are.