The amount of botched backups, restores, and rom installs from RM is infuriating. I don't think saying it's dangerous is that far off
. In reality, it's a needless interface between something that can be done simply, safely, and quickly directly in recovery/CWM.
That being said, calling him a "scam artist" or a "lying bastard" misses the point IMO. His custom recovery, for a while, was the gold standard. You know how much money he makes off of all of that work? Almost nothing. Sure, he's part of CyanogenMod (hence RM is included in any and all CM builds, BTW), but that's not a salaried position. RM is a way for him to bring in income and help out folks to get acquainted with flashing roms. Most importantly, it's a way for rom devs to find a large, established population to disseminate their work to. In that regard, it's absolutely brilliant.
Think of it this way--you go to work 9-5 and get paid far below minimum wage for all the work you do, work that is lauded not only in the work place but in the public square. You resort to moonlighting and selling something that, essentially, is a spin off of what you normally do. Is it your best work? No. Does it work? Generally. But it's putting food on the table and it makes your other work, in some regards, justified. Not only that, that secondary/moonlighting work leads a lot of people to a good amount of enjoyment, and works as a gateway to your other work and others work on top of that. Sure, it has faults, but like I said, by and large, your moonlighting work--as Koush's work with RM is essentially here--allows you to justify what you normally do, on top of other foreseeable and unforeseeable benefits.
Now, I'm not saying that I like the application. I detest it (to a large degree) and advise any flasher in my neck of the woods to ditch ASAP. It causes headaches, hence we have posts like this thread right here. But it also serves some good, and the developer is not malicious in the least with this--at least IMO, from, what I've seen, and my own personal dealings with the dev. Should he be quicker with support? Well, he should, but have you ever looked at the amount of devices he supports? It's unfathomable. Sure, it may be a quick fix--simply make RM incompatible, pull the recovery download, etc. etc. But the dev is clearly a very busy person, so taking his inaction as a sign of purposeful lying, misleading, and fraud simply misses the point and ignores the necessary context of this entire dilemma (IMO).