Ritchie Blackmore was and is amazing, but that doesn't mean Deep Purple always made awesome music, or that his music always was/is.
Machine Head is an excellent album of theirs, and Burn is amzingly packed full of energetic, powerful, organy, rock. But really, it wasn't till their first line-up mix up that they made decent stuff, but it's just like the rest of the rock of that time, with the afore mentioned albums sticking out. And no one should pretend the band that is deep purple now has anything seriously in common with the old band, pre or post break-up.
It's like saying Don McLean never made awesome music; most of his stuff is just generic folk fitting of the era, but American Pie stands alone as awesome.