Ah, you are thinking that we do not understand that the 3 minute thing causes problems in-game. Well, thats wrong, unlike a lot of other eSports companies, we are all CS:GO players ourselves. We understand that it is frustrating to 4v5 If it didn't, we could have put even 5 minutes, or 10 minutes.
In other words, on one hand 4v5 for N seconds has bad impact on the game, on the other hand N seconds should be enough for a genuine timed-out player to join back and finish the PUG.
Its all about the N above ^ , it has to be a balanced number to be fair, you can't make it too low and you can't make it too high. (In Scrims and Matches we simply pause the match but that won't work in PUGs, again)
We can discuss on whether N=3 is the correct number though. As I explained, we arrived at 3 by calculating the average time a person with a genuine network or hardware problem would need to join.