But how would you do it? You can review a penalty call easily enough because the ball is out of play. But reviewing non-calls is harder.
Do you stop play immediately? What if it's not a penalty? You've just ruined any momentum / attacking opportunity the team in possession had.
Do you wait until the ball is out of play next? That might be five minutes and several attacks (maybe even a goal) later and you can hardly bring play back then.
The main objection to video review isn't conceptual, it's working out how to actually implement it in a practical manner.
Yes, you can stop it immediately.
If it is good enough for a fake injury to cause play to effectively stop immediately, what is wrong with a penalty review?
I watch at least 1, and at least bits of 3-4 games on an average weekend - seriously, how many times would a player go down, or there be a serious, legit penalty call which isnt, and the offensive team still retaining that ball for 5 minutes or whatever?
id say never.
As soon as the defending team touch it, or it rolls out just review it. If the offensive team have it, again, they would score or lose possession within 10-15 seconds 99% of the time.
It can be a goal kick from there if a non penalty.
An absolute non issue, but good argument for a sport which seems riddled in corruption.
Clamp down on diving, ie if a dive cards can be given out via video to further stop the diving issues, and it is all win-win.
Unless you want the game to be as corruptible as possible.