Why even have the system if you're going to put in that kind of restriction.
Same could be said about the report and mute option, yet valve clearly stated number proved it give good result. Such restriction give the best of the 2 world, you can't say you won't have comeback anymore ( except if everyone begin to play only one game per week... ), yet, it's enough to avoid some of those sure loose game you know are gonna drag ( very rare if that thread is representative, so you don't need to be able to concede 10 times a week ). Heck you could even tune the thing a little with an extra concede if your last concede was successfull ( 4 other teammate voted yes ), and you wouldn't receive the next week concede if you call for one and 3 player actually vote no ).
It came as incisive because it's by far not the only time I see a post like that, which I could resume to "hey a comeback happened, so concede can't be an option because valve would allow you to concede in every match, you couldn't vote no to a concede vote, you could concede 30 secondes after the game begun, and I can throw post like that every day, but if opposing argument begin then we will have people going
don't speak about it volvo won't add it".
I'm pretty sure we could have read the same thing about the mute report if people had suggested that player with weekly limited report, could make you be muted, before valve actually did it.
For a gaming forum I find very sad to have people go for 'if a game couldn't make it work for my taste, other devellopers should never try something similar even if improved because it can only mean it can't work at all'.
Don't make Dota 2 F2P volvo it could only mean we would have to spend money on hero and rune.