What is this bile fascination with pretending that the team that used revive first magically regains perfect map control and wipes out the the remnants of the initially winning team with no cost?
Cause the 2 champions with 300 hp can totally defend that tower or even keep it neutral for the next 10-20 secs while they wait for the rest of their team to respawn and get back to help them.
Assuming that is even remotely possible (outside of the 1/500 game chance that the champions that survived the team fight are the perfect poke/counters to the enemy champions that revived and are now running top) that the champions that survived could keep that point or keep it neutral until the other 2 members of their team show up and they defend the point. The 2 injured people die, and are now stuck on 20-25 sec respawn timers while the rest of their team, 2 champions, have to defend against 4 attackers.
And the argument of "oh well then Team B should just use their 2 revives and go help defend" is stupid. Why should 1 spell perpetuate this stupid scenario? There is NOTHING skillful nor strategic about hitting a spell that brings you back to life, removes the punishment of death that you deserve for dying, and then lets you get right back into the thick of it to undo a poor mistake or a matter of being outplayed.
That's effectively the same as saying "no that goal doesn't count, we want you to retake that free kick because we made a mistake, you have to go back to square 1 and start again"