Very much, I too find thrash rather limited and it has always struck me as a sort of 'transitional' genre and I can kind of see the point of those who say the genre is basically dead and that the newer bands are mostly rehashing the sound of the prominent thrash bands of old. Not to say that there isn't good stuff to be found within thrash, of course, but compared to other richer and more diverse genres such as death, doom and black metal, thrash seems rather stale.
I'd still take thrash metal over grindcore tho.