Can I ask a serious question about match making?

Ok so in regards to MMR I understand how it works.

That said this is a core design philosophy I don't understand.

"Match making tries to make your win rate hit 50%"

Is there some redeemable aspect to this philosophy? Is there a good reason for it? Shouldn't the core philosophy of match making be "Create equal MMR teams where both teams are as equal as they can be"?

If I have 1900 MMR lose a game and get 1850 MMR it shouldn't make my team or the enemy team any different than if I won 1800 MMR to 1850 MMR but they are VERY different from a match making perspective. If I went up then I'll likely end up in a 1750-1850 MMR game while if I went down I'll end up in 1850-1950 which is a HUGE difference.