hum, I hear this said often, and it just seems silly to me. It's the total package. The person and the equipment. If it's just in the hands, then why do renowned violinist seek the most expensive Stradivari Violins... if it's all in the hands. The instrument becomes an extension of the player and is just as important. no different with gtr tone.
It's just like quality engineers and their gear. People often ask the same question; if the gear is not so important, then why do the best engineers have the best gear? And the real answer is because they have the skill to use the stuff well, and they use the stuff well to take their work that extra 5%. But it's still 95% in their hands.
It's also just like the story with mastering; these all follow the same theme. Quality mastering, like a fine hand car detailing, has the greatest impact and the most use on the mixes that one would think needs it the least. A Blue Coral car waxing is going to have much greater impact on a brand-new BMW M7 in the showroom than it will on a rusty old '72 Pinto.
These musicians pay big money for their instruments a) because thy can

, b) because they actually know how to take advantage of such instruments, and c) because they know they have already developed their sound via their technique, and they're picking the stuff that will take that sound the extra 5% of the way.
Give me a Stradivarius, it sure won't make me sound a thing like Itshak Perlman. It probably won't even sound like a Stradivarius. OTOH, give Itshak Perlman a West Virginian fiddle covered in coal dust, and ihe'll still bring you tears from beauty.
And, to put a fine point on it, it's not just the *sound*, it's the caring about the *sound*. You ever notice that the better the musician or the better a guy *sounds*, the less you hear them talk about or worry about the *sound*? And I'm not just talking the Nashville Cats and the superstars; I'm talking about those guys sitting at the bar waiting their turn on jam night.
Watch them set up their gear at the beginning. You'll have two guys; one who spends 3 minutes tuning his strings and loosening his fingers, and then goes and waits his turn. He's usually the one with the black nylon shoulder strap. Then you have the guy with the UV-dyed snake skin shoulder strap who spends a half hour up there setting up his half-dozen pedals, and fine tuning the knobs on his heads and his guitars, hitting power chords left and right until you just want to rip the AC cord for his amp out of the wall before he has finally dialed in just the "sound" he wants. You want odds on which one will actually sound better? Let's just say it's almost never SnakeBoy.
G.