Are Salesforce developers, really developers, or bottom-feeding conmen?

That depends what are you doing there. Personally I don't think about my self as "bottom-feeding conmen", but I can understand what are you talking about.
I see several types of people there:

"I am developer but I don't understand the platform, so I write code that could be replaced formula, workflow, I'm hitting the limits and I hate SF" - it's almost as java developer trying to write JavaScript.

"I am junior that knows something about the platform but don't know how to code, so I write shitty code." - this I think is the biggest group, especially because demand for SF specialists is very high, and juniors are used as mid/senior developers.

"I know the platform, and I understand how to code, I can do more than simple business logic. Platform has a lot of cons, that make my life harder, but there are also some pros." - here we have group that is constantly shrinking since there aren't many challenging projects on SF, and good devs can change platform/language without a hassle.

Nah. What I mean are the vendors pimping their Salesforce intrinsic apps to the already ignorant enterprise business.
Take for instance CRMFusion's job builder. This little gem tried to make up for its companion, demand tools (which lacks a scheduler to run batches, which, in itself is already retarded). It FUCKING generates a .bat script (I am not shitting you), to spawn an instance of development tools and instructs the user to have previously checked the "remember me" so it can "auto-login". OMFG!! Really? This not to mention demand tools own liberal use of the API calls (read better watch your enterprise API cap).
Proprietary stacks like Salesforce will soon enough be a relic of the past. Salesforce, though, I think takes the cake. It propagates it's variant, proprietary API while leading a symbiotic leach army to service it's base.