Seems like something that would change the game significantly, and I feel negatively for that matter.
A lot of the really tough decisions that need to be made (along with execution) come with the pushes onto 4th CPs. Removing points like spire (one of the most interesting & studied points in the game) just seems like you're removing a big chunk of the game. The game may be sped up, sure, but doing so removes x amount of possible interesting situations that can arise in the game - leaving us with a lot less possible things to see occuring in games.
Look at it in the perspective if you were to do it to another game: imagine if duel maps in quake were limited to only a yellow armor, an LG, and a rocket launcher with 2x 50 health's. Sure, it'd be fast and "exciting", but you're removing SO MUCH from the game. I guess this isn't the best analogy since quake3/QL was a 10 min duel to whoever got the most kills, whereas TF2 is first to 5 and 2 30 min halves, but it should still give some idea of what you could do to the game.
I mean, Starcraft games can potentially go for 3+ hours in a bo7 (mind you the different game speed, and the stars would need to align for game series to go for that long consistently), that doesn't stop it being a good spectator Esport.
I think stalemates are good. I mean sure, 10+ minutes attacking/defending snakewater last can be seen as "NOT FUN", but the good stalemates that occur between mid -> 4th CP are where you get to see the decision making by each team, and whether they prevail or not because of said decisions. To be fair, the only reason why extended stalemates happen are because the top teams are so close in skill/knowledge, that it can be said that it's a mutual respect to the other team where they're basically saying "Hey, we can beat you on even ground, you can beat us on even ground. We're going to play this until x gets an advantage, then whoever has the bigger advantage WILL (should) win". To that credit, good stalemates happen at last attacks/defences also.