I don't believe rightness applies to opinions. I agree with you on that they can be sickly formed, but it doesn't make them incorrect in any way, because they're a piece of subjective perception of reality, just like a fact is a piece of objective perception of reality. Here, let me do a run for it so you'd understand what I mean:

Opinions can conflict with fact.

"I believe the Earth is spherical rather than flat".

Opinions can be undesirable.

"I believe people ought to be treated equally, no matter the color of skin" to a racist's face.

Opinions can be immoral.

Opinions are amoral, intent can be immoral. Believing in solving overpopulation through killing off people bears no morality on its own, but the intent behind it is immoral. This, of course, raises the question of whether opinions and intents behind them are separate.

Opinions can be dishonest.

Expressions (words, phrases, sentences) can be dishonest; opinions in themselves bear no property of honesty or lack thereof. Again, a question is raised - whether expressing opinions is separate from expressing any other personal thought - but that's beyond my point.