I think the main ‘issue’ that people have, is that a class trinket that is considered very rare, should be good for you, if you are lucky enough for it to drop and you win it.
The issue I think that OP was raising is that the proc effect seems exceedingly abysmal for some of the classes that the trinket is mentioning, but other trinkets for other classes would benefit that class more.
It’s a 5-class trinket though, so IMO the impact of it being sub-optimal is less (It’s also difficult to make a single trinket amazing for 5 classes), i’d be upset too if it was warrior-only, but now it’s a relief, if anything.