It's one of the rare features of this game that helps manage game shape so it should stays this way.
Things aren't necessarily as rosy and straightforward as you think. It's a way to manage game shape IF you have an expected blowout and plan for it. I understand that such situations allow you to field the same starting lineup 3 games in a row and garbage time will play to your favour. But there are games where teams throw one out of three games in the week, and if you just so happen to come across an unexpected blowout, things can really go haywire.
That said, the first sentence of my post did propose for the best of both worlds - managers who love the feature can keep it, while managers who don't want it actually can choose to play their starters like a normal game. That would be an even better feature which helps you manage game shape, wouldn't it?