I'm telling you it works and I've been a part of multiple thousand point comebacks because of it. It's pretty much a Battlefield technique. The team doesn't rush from point to point, they sweep to the next point making sure nothing gets through. And it's not obvious as no one planned it, it just happens organically once a team gets pushed to a certain point. It's gotten to the point where if my team is far behind early, I expect us to get even by the end of the match.
Of course not, but I've yet to have a match with randoms that has had a lockdown for more than a few seconds. If you have an organized fire team, then yea you can trust your teammates to do their part, but in randoms, the best you can hope for is people to get fed up with the back stabbing and just be thorough on their way to the next point. And usually it happens.