I guess that what you really meant was “change your PVP matchmaking”, and not “fix it.”
Unfortunately, PVP is made to work just like that, those big boys disputing among themselves, which one score higher points, by simply hitting weaker opponents as fast as possible. If D3 changed it, those big whales would have to always fight among themselves, making the game “not as fun” anymore.
Just watch the amount of players joining brackets in the last few hours and getting top rewards. It’s only possible because they have weaker opponents providing lots of points in a very few space of time.
So, just like D3 changed PVP back from a win basis system to a score system, without even trying to make it better, as not to piss those players off, I’m afraid you’ll have to just accept it or find another game.
And by the way, as I have no 4 stars boosted this week, just had my 3 stars team hit by 5 star one so...