I blame the rise of more effective DRM and the removal/demoting of lan play in favor of hosted servers. All of my favorite RTS games were discovered while at a friends house. We’d do a quick copy and have an epic game session, creating a legend game that I’ve bought multiple times since. Studios should allow copying of games for some purposes like local multiplayer, but protect single player and internet content with IAP, so that the game spreads virally, creating a large market and a strong brand.

This was exactly how many of the classics got started, but back then it was in spite of the studios intentions. I think a good rts could still spread that way but now players would welcome the IAP, as long as core mechanics are available and it’s not pay-to-level-up.