I feel where you are coming from, but like Names said, it will just lead to more/faster capping. On the plus side it would no longer win them the game, but it would give a pretty big advantage and force the enemy team to form a clump somewhere as anyone that strayed from the group would be taken out fast. This sounds like a fun game mode, I'd definately like to play it, but it's not what I would like to see assault changed into. And you also have to consider that there are people that like Assault like this, granted most of them are probably light pilots that group into a premade and swarmcap, but they have a right to their happiness too I guess, it might be the only way they can win and feel like they are "l33t g@m3rz."
What I would like is a new/different game mode. Conquest/Assault are basically the same thing, stand in the square long enough to win or actually fight enemies. The only difference is the amount of time and squares, so it's getting really old to me. I want to play MechWARRIOR, not MechSTANDER. Thankfully they mentioned testing a Skirmish mode, which I really hope will not include any bases, and just maybe one day we will get a 1v1 option for duels/training.
The only thing that I would like to see in Assault mode is them getting rid of the bases, but then that's Skirmish lol. I'll vote that it's a good concept, but not perfect, mostly because it would add a much needed new element and interesting tactics to the game.