Well. Regarding concede, DOTA 2 chose specifically not to have a concede option. I was against this at the beginning. Then, there was a match where everyone wanted to quit, we were bashing Valve, but we fought anyway. We had a huge comeback due to a huge Blackhole from Enigma. I've changed my mind since.

It sounds weird but I think it taught me to be patient and to fight till the end.