It's wrong and always a problem when people start lying, either to themselves, others or both.

I agree there is nothing wrong and people advocating for their preferences, opinions, arguments, solutions, whatever.

However, when you get so attached that you need to start lying to say it's better or that the alternatives are worse, that's no longer rational and makes the people doing so no longer trustworthy.

This is true for all types of tribalism across all areas of society.