[nmfisher]

I follow a bunch of people on Twitter who have tried to do this at one point or another.

Money never seems to be the sticking point, the problem is (a) figuring out who actually owns the rights, and then (b) actually tracking that person (or company) down. If we're talking about games from the 80s and 90s, many of those rights changed hands a number of times and the people/companies involved have since died/dissolved/retired/disappeared off the radar.

Another very good reason for a shorter copyright expiration period.

[ThunderSizzle]

Doesn't copyright require enforcement?

If no one claims it or enforces copyright, then nothing is stopping anyone from attempting to work on it, but without the source, it'd be all reverse engineering or something to that affect.