I fucking hated that upkeep shit in WC3, seemed like I'm just being punished for having good macro. Also not a fan of hero units. SC2 definitely suits me better.
Like i said, without upkeep losing a single skirmish would have meant instant game over. Maybe that's fine in a game like Starcraft which is more fast paced but WC3 was intentionally designed to be more of a slow burn. Like i pointed out earlier, during the first two minutes of the game you are essentially locked into producing your hero and unless the enemy base is really close the next several minutes are spend creeping around. So aside for some scouting and maybe a bit of early harassement that's a solid five minutes you are spending basically playing single player and then maybe you get into your first big skirmish and suddenly you lost too many units and the match is basically over because there is no way for you to recoup from that. Wouldn't make for a good game since it would be the same outcome every match. Spend five minutes setting up your base, creeping and scouting around then lose the first fight and quit, rinse and repeat for every match.
Personally, i think WC3 is one of the most brilliant games Blizzard has ever designed, possibly the best they ever did. It's a fast paced RTS game with integrated RPG elements that even plays like an RPG during online matches. It's fine to prefer Starcraft as a matter of principle but WC3 feels more daring and it's more impressive that they were able to pull it off. It was a big gamble for them try something so radically different and counter intuitive given the nature of RTS games.
Even if you prefer the more macro oriented nature of Starcraft you have to appreciate how WC3 managed to really set itself apart from that, where as it could have easily just been a fantasy reskin of the former.