It was a Sierra game, and Sierra was absorbed by Activision
It was made by Relic, and Relic was absorbed by THQ
And there is a good chance they both own some parts of the rights, thus making it difficult to negotiate.
THQ straight up owns the Homeworld brand, so I imagine there's still some publishing agreement that stops it be distributed for the moment.
I just purchased the original Roller Coaster Tycoon pack from GOG today. Saw it on sale for $2.99 a few weeks ago and didn't jump, ended up paying $6 but still an awesome deal.
How obscure are Toonstruck and Bermuda Syndrome and how available are they because those are two games that I'd really like to get a chance to play for longer than their respective demos last.