Οk, I can accept that but you did not answer why a butyl tube would negate a high tpi tire's ride quality. I agree a latex tube would ride even better but still with a butyl tube you can instantly feel the difference between a 300tpi and 100tpi tire.
At least my personal experience with a lot of different tires, lower and higher tpi (including Continental and Vittoria) was that higher tpi tires (open tubulars) were always feeling much better even with cheap butyl tubes.
Fair enough. Open tubular is just a marketing ploy though. It's a clincher. It's effective of course. People think they are buying into a superior product that's closer to a tubular. It isn't a tubular because it isn't a tube.
Perhaps the high-end tyres that aren't advertised as high TPI find another way to compensate?
Is there any independent testing that TPIs are what manufacturers say they are? Or do we just take it on trust when we should all know better?
Sure it's a marketing ploy but that does not make it false per definition. If ever you'd see a clincher advertised as an "Open Tubular" when there is no evidence of a tubular brother tyre then we could all shout "foul play".
Ask yourself, how many true clinchers are there with a high true TPI count? Not many if any at all, I reckon.
It's only lately that companies such as Schwalbe took the tech of clincher building to a higher level (let's just say they're trying hard for the moment) yet all of their know how came from a tubular manufacturing company they took over.... Irony?
See where I'm going?
That said, I do not think TPI count is overrated. Unfortunately it's often misrepresented to put it mildly....
Combine high TPI count and modern compounds and you'll inevitably end up with a very fine tyre. High tech compounds combined with low (true) tpi count tyres OTOH will not show fine rolling resistance figures unless you go for the wider ones.
Can't have your cake and eat it too, right?