Seriously? You quoted a post by wikus as evidence. Not sure what that is supposed to show.
The courts consider "majority market share" plus "anti-competitive practices" among other factors in deciding whether a monopoly exists.
Apple clearly has the market share, and their business practices (such as this nonsense trade dress lawsuit) could be interpreted as anti-competitive.
Apple should be slammed, and slammed hard over this nonsense. I hope that Apple loses far more than any temporary advantage over Samsung would have gained them.
Your understanding of antitrust law is a bit simplified. I like how you left out the "among other factors" in deciding Apple is guilty. As if they aren't important. Abusing a monopoly requires more than just market share, though market share is a significant factor. Durability of the market power is another important factor. You are not going to see an antitrust lawsuit in a market as new as the iPad market.
And, of course, suing a competitor is hardly an anti-competitive action.
"Convicted monopolist" would be a good tag for Apple.
And we get to the crux of your argument.