I don't speak for the MAME team or anyone but myself with this.
Okay, seriously, what the hell is wrong with you people?
Let's get some basic facts straight:
This relicensing project has been ongoing for a year now, with repeated comments about needing to find authors of code chunks to get permission to relicense. It was DISCUSSED in public and private for at least two years before that.
If you were doing a *DERIVATIVE* build of a project with a custom license that needs to contact old coders to relicense, why would you not think "Oh, hey, I need to look into my own old code base and contact people!"?
At the very least, you could have had the forethought to ask.
If you didn't at least do your due diligence and ask questions, you have nobody to blame but yourself.