I think anything can be a scary house if done right. I just think consensus in the old-timer HHN community is that Cold Blind Terror one of if not the worst from an otherwise solid year, which kinds of make it Everest, just begging to be climbed. Solid ideas, btw, could definitely work.
Patient Zero was just alright for me, with some clever ideas. It's nowhere near the same league as the original Dead Exposure, which is still one of my top 10 houses. If anything the sequel suffered for having to live up to the name.