you'd think they'd at least spell check their spam
It's possible that the spam has randomly misspelled words and phrase segments to avoid filters. Another forum that I visit has very similar messages, but sometimes they're rearranged, with different words here and there.
And the HTML is probably because the spammers haven't got half a brain to their name, or they're also using the same message on different types of forums, some of which use HTML instead of BBCode.