They probably have contractual restrictions - agreements to help fight against unauthorized copying, or to protect the copyrights of people who create games on the system.
And in general, most console systems are a serious bundle of hacks, mostly tolerated by programmers by the sole fact that you can rely on every system to be identical.
>I don't know. Winning people's hearts? For the fun of it?
That's true, but as long as they can still make money from their IP they won't (i.e. repackaging old source + game(s) into a VM for sale on Steam or next-gen consoles)
Some of the source code/etc may be licensed from a third party, which means that releasing it is treading through a legal minefield.
In cases like these I'm thankful for pirates. When an interesting project is about to die because all the stakeholders lost interest and there's too much legal mess to deal with to give it away, it's good if there's someone that steps in, ignores that legal mess altogether and simply dumps the product on-line.
What's strange is that a lot of the Sega games from this era are just missing completely. Try hunting down Skies of Arcadia (even the GC port) or anything Panzer Dragoon. They were never released in virtual consoles despite significant cult followings.
If there is one thing I learned from internships and various jobs (I'm still a student), it's that companies pretty much always exist of people who care. If there's an opportunity to spread the name SEGA around without any downsides, good odds you could find someone in the company who's up for that.
Trouble is, you probably need to find whoever was on the original product team, or it's going to cost the company more hours than they'd find it worth.
