and it is enough incentive to raid?What is a set when there is no set bonus?
Those are tier sets - do you see set bonuses? Because I don't.
Bonuses aren't the necessity of a set, really - a Tier Set is mostly a set of items related thematically to the class and certain environment.
This way you can have them dropping in respective raids, just for a transmog/collection purposes or as a part of a bigger design idea. They could be named similarly, form a set inside of a Wardrobe, but lack restricting bonuses.
And about them being ugly - that's just an opinion, and if you don't like it, you can always transmog over it.