It's telling that they just dumped the ROMs without the source. The source would have been something, or even an address list. But apparently they are too insecure to do so... or they don't have source anymore to begin with.
If Sega's development process was anything like I understand Nintendo's to be, they wouldn't have the source to third party games anyway. If we assume this to be true, what was submitted was likely one or more floppy disks with an binary image or spanned image of the game, along with some information about what kind of memory mapping to use. I think you are drawing sinister conclusions from what is likely just a plain end result of the game submission process of the day. I also can't imagine licensee developers have ever been required to submit source code to a game publisher or gatekeeper like Sega or Nintendo. That would seem like an incredibly lopsided agreement.
Not to mention that ASM source with labels is not a great aid to programming, particularly on a system as constrained as the Genesis.
So it's bad that they didn't provide any sort of reference information about these ROMs, but it you think it would have been useless anyway? I can understand that you might be partially thinking out loud, but this is slightly confusing to read.
But now users have shown they are desperate to be fleeced, and the gates of exploitation are sadly swung wide open. I don't think it will last... I think programmers are gonna rebel rather shortly. I think there will even be unions and anti-maker contracts drawn up to prevent this kind of thing from continuing. But in the meantime, we get to watch the sad spectacle of self-debasement that I'd hoped I'd never see.
I've played many games over two decades that had an active modding scene. People that play mods play them because they want to continue feeling a similar experience that that game created, or even a superior one. What you see usually is that people with a dramatic surplus of time (people who are still in school) are the ones creating these mods / hacks. Myself now being much older I find it hard to justify the expense in terms of time when I am getting paid at a real job. It seems to me that you assume everyone is static and isn't constantly reevaluating the costs and tradeoffs of participating in a modding community. I started off feeling like rom hacking was an cool, altruistic activity, labors of love you know, and I still do. But I have more skills now and less free time. If I had plenty of time and money, you can be sure I would be feeling more willing to dump time into these projects. And obviously that is my own analysis, some people will value their time differently.
I think your criticism that releasing maker software to users who have no hope of using them gainfully is also overly cynical. People play games to waste time and more importantly, be entertained. Not everyone doing it is out to make a buck. Most people that have given it more than a cursory thought will realize that if you want to sell a game you will likely be forced to create your own intellectual property. Also, as for "anti-maker" contracts. I think you're missing the point that for a maker software to be appealing, you have have some intellectual property in play in it that is appealing in the first place. That doesn't put programmers and artists out of a job. I would find your argument more compelling if game companies were crowd sourcing their level designs and art design from customers and then turning around and repackaging them for sale with no compensation to those users.