Hello,
Wouldn't that be an endless discussion here ?
I think, as probably most of you here, that bikes are a matter of love and passion (at the point that I don't even consider bikes as a means of transportation, that could save my ass sometimes, but no). Bikes only equal fun, bikes smell vacation, good moments, I never have had bad thinkings about my bikes (even a flat or, let's say, a crank that doesn't want to stay in place - my 1st MTB back then -, it can bring new experiences and from that, it's always possible to change "bad" in good memories).
That's, I, how I see things. With each bike I lay my hands on, I want to have fun. I like to have an idea, then find the components to make all the thing grow up. I can, at a certain time, be in the mood to try to make a period accurate/by the book/specs-"right" bike. And at another time, be in a mood for a more exotic bike. Like the evolution of a concept, an idea that becomes something real. For so long I have been someone who thinks, who reads, who writes (and I'm still this one), not much of a guy who tinkers. So, the very idea of making something from scratch with my own hands is challenging and very rewarding.
In either case, what I like is the process of finding the components, the search for them, and all the learning around. The assembly is also a big turn-on, and of course the riding. The main thing is the fun.
These days, I'm assembling a vintage singlespeed CX bike. Have learned a lot of things about those. I like the minimalism of it, the looks, the esthetics choices I made (why in the hell would I assemble a bike I don't find attractive ?

), I have also tried to do something that has all the distinctive traits of a CX bike from the seventies or the eighties, with a mix of period-correct components and new but technically accurate ones. Also trying to replicate the subtleties of this type of bike (tyres, of course, brakes, ratio, cable management, dashguard…). Should be very fun to ride. I don't have yet all the components (the last ones should arrive very soon) and I'm dying to see that finished now. I'd like to ride it during my vacations in ten days.
My point of view is very similar, if not identical, to MattiThundrrr's : my bike, my project, I do what I want, don't care what others think. I should add that I'm also trying on each of the bikes, to make them ride smooth, always mecanically in perfect shape. Don't care if there are some degraded paint here and there or a little surface rust, but everything must work perfectly.
W.