I read your link, and i think its good, but this system has some serious flaws
No flexible role for one hero
How with hero with many role like sven, void, eartshaker, witch doctor, and especially invoker? he is carry, nuker, escaper, support, disabler, initiator, etc. How system evaluate him? Just spam invoker and BAMMM you get high mmr. Poor pure carry/tanker/nuker etc, they will get lower mmr, and FYI many people just wanna use one role like(oh i wanna be hero so i pick carry forever, or Oh i woman so i just wanna support forever, or something lime that)
How about new players? like people say, hanging out with smart people make u smart, and hanging out with idiot people make you idiot. And i experience it myself. In dota 1 I just cannot improve myself, because people just wanna play with someone he know good, and once you not good, its hard to me to play, because so many high rank lobby but very to none lobby for noob players( well because they have enough blamed). This is the point where LOL steals dota players and i think valve recognize this. So valve use ELO system so new players can enjoy this game
Many new player didnt even know what to do list with their hero
If this system implemented, there are one or two possibilities will occur, one is good player will always get play with ease, and noob player must wait loooooong time to play, or not play at all, or good player will complaint again, why noob get in to my team?
No new players = loss income potential. Nowaday so many similiar game like LOL, cs, hon, etc. Not to mention rpg game like lost saga, rf, rohan ragnarog, etc. If u bored or sick with dota, just play another game. Beside, long time players not always buy what valve sell, give valve profit, and valve is need some money for running this game. I just ask you, how much money you spend to valve/dota2 ? Be thankfull because at least all hero is free to play