Well, interesting opinion, but I'm not sure what the dilemma is! There is no comparison between the Street Tripple and the Thruxton. One is a modern hi-tech screamer, the other is a 1960's retro-styled café racer.
Although I love both bikes, I prefer the café racer style. To say the Thruxton looks like one of these "naked" style sport bikes is absurd! They share NOTHING similar mechanically besides the obvious two wheels and engine. The engines are not even similar, the frames couldn't be more different, and, frankly, share NOTHING in appearance or mechanism.
Every bike I've ever owned, be it an RD 400, KH 750, Norton Commando, or whatever, I have allways, almost immediately after purchasing them, went after the easiest, cheapest BHP (exhaust, intake, air filters, carb jetting, cam shafts), not because I bought a bike below my requirements, but like everybody with a bit of adrenaline in their veins, just had to squeeze every little bit of power out of what we had. It's true of the guy who buys the Honda Civic, AND the guy who just bought the $400,000 super car! It's called tuning!
As far as spending thousands of dollars tuning your new ride goes, if you have it, why not spend it? I like the Thruxton so I bought one. Over time I've changed things here and there to make it my own. I didn't think "oh shit, I should have got the Street Tripple! In fact, if I had purchased the Street Tripple, I would have tuned the shit out of it also! And NOT have thought, man, should have got the rocket III! IF I want to spend 5 grand on top of what I paid, so what?
To call a Thruxton an "entry level" bike is obscene. It is a 900cc twin, has Pleanty of torque and jam. Far from being an entry level bike, it's the pinnacle of technology as British Twins go! You have to compare apples to apples. I've had many Triumphs, Nortons, BSA's, etc, from the late 50's models up to the 1980's. when I switched to 750 kawasakis, and the sort. Two of the fastest bikes in the 80's were both 900's, and there was that 350 that gave them a run for their money also, but their 1100 cc counterparts were just a little too heavy and just a little more unwieldy. But getting back on track, ride an 850 commando, or a 750 Bonnie,( once the fastest bikes in the world) then jump on a Thruxton! It's so much better than what was, and with the carbs, coil / overs, single front rotor, chain drive, a fair comparison. It blows the older ones out of the water!. You can't compare the performance to a St. Triple, however, and you shouldn't, but as far as the Thruxton being entry level, forget it.
People love to get the most out of their rides, be them cars, bikes, boats, whatever. Some people have more ambition than others, and are willing to put a bit more money ino their projects than others, it doesn't make them wrong! I just paid $2800.00 for two distributors and a pair of rotors. They happen to be the only ones available to fit the car, no aftermarket at all! But I choose to own that car, so be it!
I don't understand why it's a dilema for you. To each his own. Others do a lot of things we don't understand, but that's OK, right? We don't have to let it bewilder us! Clebrate our differences, think of all the cool custom bikes out there because some people think" that bike is cool, but mine is going to be cooler!! There are more customs around than factory, it seems!
Stay cool man, don't let other people's decisions get you down, just do your thing!
Cheers!