Personal experience, I guess. 40% winrate is not fun.
By and large the average person in-game is a worse melee than ranged, and then it’s a self fulfilling prophecy. You always get beaten, you are salty, you don’t have an opportunity to learn (see thread about smurfing to learn), so you use melee matches to drop MMR and then dominate with ranged.
I am generally encountering people who are fairly bad, considering their plays. I’m seeing fantastic ranged plays by Bronze 5+0 folks. But melee players are, you know. The Illidan stereotype. The Qhira stereotype. The Diablo that keeps diving to suicide.
Look at my profile to see MMR per hero, and it’s glaring that apart from 1-2 heroes that somehow click, I’m as extreme between two heroes as pretty much the entire ranked league. I can’t even deliver with Mei and DVa, and those heroes are supposedly terribly OP.
Therefore, if you see me pick melee, except Anub and Qhira and maybe Varian, you can report me for throwing. Of course I can kick butt in Silver 5 but that’s salty, too.
Partially because about half of melee matches have no healer, and that experience is just pure trash.
Fix the system, introduce hero-specific MMR in QM, encourage playing wanted roles by getting massive gold (instead of xp, so that you can buy a chest) and progressing all quests. Show MMR in QM. As this will normalize every hero at 50% winrate, compare per-player MMR values.
… And once you learn how to play without a tank and/or healer, you really don’t need it. Arguably a QM player is superior than a SL player in that regard. But also I’ve seen tons of SL matches where the team without a tank has beaten the team with it, badly. Damage adds up beautifully.