Not too sure where this thread is drifting, not sure I'd want to try to define "boutique builder" myself. I've experienced Trek-think. I've also been to a few NAHBS, seen/met some very new builders, some recent builders and some old-timers. You can talk about the frames themselves, the builder's experience and skills, the builder's business model/viability and the builder's impact on the industry at large. Since this started as a discussion of beautiful modern lugs, I'll say that one thing that strikes me at the NAHBS New Builder tables is how many very competent-looking frames I see that, except for paint/graphics, look very similar. It's like 4 or 5 of the builders ordered the same framebuilding kit from Nova Cycles, with the same lugs, built it, painted it/had it painted, and put their name on it. Absolutely nothing wrong with that, they all generally look nice and probably ride nice, and you gotta start somewhere. But other than paint choice and graphics there's sometimes very little differentiation, very little of the builder's vision and individuality visible. Builder A's Long Shen/Pacenti fancy lug doesn't look any different than Builder B's.
Then you look at a Columbine, DiNucci, Bishop, Ellis/Wages, Chapman, Cherubim, Watanabe, Royal H, Bohm and a bunch more. You look at the tube/lug/bridge choices, the lugwork itself, how whether the lug treatment is ornate or simple, the builder's rendering of lines and flow just pull you in. That's where you see the artistry and not just the craftsmanship. You can argue it's not necessary, not worth the $$, won't make the bike ride any better. I'm just grateful there are people compelled to build things of beauty that speak to me. I'd have to sell a crapload of C&V bikes to afford any one of these, and I'm just not that disciplined, but I like to look...
I would not discount the effort to make a quality frame and fork short of adding styling to it.
Problem is that the result will appear generic.
If I selected the two images I wanted correctly the first will be a Nobilette Herse.
He fully translates the Herse look. It is interesting that frames with his own name do not get the attention his work for RH does.
Styling is some of it.
Many builders don't have styling down. Should have gone to design school. Even guys like Richard Sachs though took years to develop a style, for him, thank goodness for Masi. He gets a break as he was going to be an English major.
I do think there still is an association with many that decorative lugs denote more effort or greater care in construction. A throwback to the time where detail denoted high quality.
For the record I think the huge seat lug extensions above the top tube are just plain silly.