I've read someone asked in a review "what's all this hatred due to playing both roles about", that's how I know there must be people not happy about it, but haven't read a single comment why.

Honestly, I don't know why people think it was a mistake. It's a possibility, an opportunity, it's something different than just playing one role, but each to their own.

I hope to read your review on the movie. Give it a try.