He can't direct a movie anymore to save his life. House of 1000 Corpses is honestly a super iconic horror film that pays great homage to films like the original Texas Chainsaw Massacre. But like you said, his last few films have been just dreadful. Honestly, and RIP Sid Haig, but 3 From Hell was so awful that it heavily changed my outlook on Rob as a director.
And there was literally 0 reason for it to be made. Like I said, there's no way in hell the Firefly's should've survived that shootout at the end of The Devil's Rejects, the cops shot the fuck out of 'em. It's clear Rob had nowhere else to take them nor should they have warranted another movie, yet here we are. And to make matters worse, they had to cover for Sid Haig's death (R.I.P.) by having Cap Spaulding get the death penalty when the other two were just as involved and just as guilty as he was, yet they got life, it makes no sense, but then again, the quality of RZ's movies has dropped substantially since TDR, so this shouldn't come as much of a surprise.