Right, they won't be offensive to everyone, but those mentioned, surely to some. There weren't any made up reasons there, they were all true imvho. Maybe not to you, but if you weren't getting worked up about the word spastic, the original post doesn't really apply to you anyway.
But your examples further expounded the point, which was agreeing with a previous post made by someone else - this extreme reaction about the offensiveness of the word 'spastic' is mostly because of the artist who made it, whereas other potentially offensive shirts/titles/messages by other artists would 'get a mild footnote'(well put!). As the exampled shirts and derby theme did receive - a few people doubting, but not the outrage as seen in this thread. Plus this is just the title, which woot often changes, not even the actual message of the shirt -- so why the drama over this? Because it's by an artist that people tend to get up in arms about.
The point of the post was just that - to agree with the quoted post, and to add the observation that people are selective about their outrage (at least out loud) to things that are potentially offensive.
That's all folks, nothing more to read into.