After years of yearning for Eclaire, my desire was bursting!

Why don't we get a good live action adaptation of anime?

I would say that there are two big categories of anime, the action ones and the talking ones.
The talking ones for some reason usually don't get adopted into movies, they are mostly romance or comedy.
The problem with the action ones is that they usually need a considerable budget to achieve the same level of action as the original.
This is because manga and animation are only limited by imagination and not any of the technical stuff, where as movies are.
Movies like Dragonball, other than the stupid story and cast, the effects just don't look right or as good as anime. Real people don't have the wacky hair.
You can;t have huge spikes in your hair, you can't have red/pink/green/blue hair without looking incredibly stupid.
Real people just don't look good in anime hair for the most part, but hair is one of the most important ways of identifying an anime character. Another important part of an Anime character's identity is their physical build.
Real actors don't have the same kind of exaggerated features.
Taking Dragonball for example again, Goku is just stupid without his muscles, everyone looks so skinny and weak.
Most cute female characters don't translate into real people too because of their face. They don't speak Japanese, but Japan doesn't make most of these movies, nor do they have the budget to make a good one.