I recently had a conversation with one of the friendliest businesses I patronize (an espresso bar in Sydney). The owner swore like a sailor about an ex-staff member who'd come back with the keys he'd "lost", and stolen from him in full view of the security cameras.
You need to know our audience, and to have chosen the personality you're prepared to project as your businesses spokesperson, but DHH (and Ben) have clearly both chosen to be perceived as "guys who'll use strong language when people steal from them". That choice might not "work" if you're in the clergy, or a school principal, but making that choice as a café owner or software company spokesperson falls a long way short of "not acceptable", at least in my book.
It's always impossible to measure the _really_ interesting stuff, but I wonder if 37Signals earned more benefit from people thinking things like "DHH is _really_ passionate about his business." than they lost from people who though "he used curse words on Twitter, I don't want to do business with him anymore"? (Patrick? How do ou a/b test founder personalities for conversion rate? ;-)
Big