Look, I get it... everyone hates the black bars.
What I don't get is that every TV you have owned since about the year 2000 has been a 16:9 TV and when you watch movies from Blu-ray they have always had black bars at the top and bottom.
This is a well established concept. Yes, you can zoom in and fill your screen, but you are changing what the film actually is. How it was shot. I agree that it's absolutely crazy to throw away part of the image because you can't handle 'black bars'. Your choice of course.
But, why not look for solutions?
My theater plan is to use a large 16:9 screen and to put it on a black wall. Then, I will have masks I can add to the screen when I watch 2.35 content. The masks will just be held in place with magnets, or I will use a motorized shading system of some sort. But, the ability to mask a 16:9 screen to 2.35 is not unusual and changing the format of your screen to fit what the director wanted you to see is far more better than changing it to fit your screen.
Everyone can do their own thing, but I certainly don't get why anyone would change it.
You turn this:
Into this: