The movement 3 hurts. Having to carry 2 subpar models hurts. They’ve not placed in any GC this season.
As good as Gurzag is, Skritch is kinda just a better 1 model army and Skaven have the results to back it up. As far as the multiple durable fighters goes, Magore is a better option there.
There’s not really a niche for Orruks to slide into right now without them just feeling like you’re playing a worse version of another deck.