A developer making his product worse over personal bullshit would outweigh almost every other consideration, especially in such a competitive market.
I'm guilty as the next internet-person of over-reacting. I can see no reason to be upset about someone else doing the same, whether it's Marco, you, or any other reasonable stranger.
But in the end, I don't care if it was malice or incompetence. I refuse to believe person who made a mistake and apologized > person who never made the mistake in the first place. Learning is fine, but some things you shouldn't have to learn.