I don't think of Rivera as a boutique amp. They are high quality, but still PCB amps.
They are, if you like, the BMW to the DSL50's Mondeo. No-one would object to paying more for an Audi or BMW than the equivalent Ford or Vauxhall.
The Rivera is aimed at pros and semi-pros. I have one customer , a professional musician, who's had a Rivera combo for over 10 years that he uses 3 or 4 times a week. I gave it it's first ever service a few months back, and it needed no attention, other than a clean.
"Painfully expensive" does suggest overpriced to me, which I wouldn't say the Rivera is.
To my cost, I often come across the squeamishness about spending big money on an amp! :(
Maybe you're right about the bling. Walnut cab anyone? :)