Here is something else that came to mind. Heroes 3 SoD is a social game, whereas grindy games like Starcraft-Warcraft - Counter-Strike - are antisocial. In particular, you can be a good player in Heroes and still have a successful job, a personal life, and sometimes even a family).
The amount of grinding in sc-wc-cs is determined by the fact that these are games based on precise coordination; a break in training reduces the speed and accuracy of actions. But in Heroes, for most features, it is enough to learn them once and you've already remembered them. You can go without playing for a couple of years and restore your game form in full within a week. This applies to both SoD and VT.
