On a question like this, I want to place my own experience (though I've also played with 8 modern clubs or 11 vintage ones and found no appreciable difference in my score) behind that of the greats who've played the game.
I think of Ben Hogan praising Jimmy Demaret as the best shot-maker he'd ever seen; saying something like "I ended up being able to hit all those same shots -- but it was Jimmy who was hitting them first, and that's who I learned them from". Or
Byron Nelson, on being asked as an 85 year old how much better his 18 win season and 68.3 scoring average would've been if he could've used today's equipment, answering: "Oh, probably not much better. The centre of the club face is the same now as it was back then". Or
Nick Faldo, emotional as he remembered how he marveled at the shots Seve could hit and the imagination he had, the 3 woods out of fairway bunkers, the laid-open 4 irons out of greenside bunkers -- and then getting teary-eyed with pride and affection at how Seve hugged him at the end of that Ryder Cup and said "You're a real pro!" Or
Trevino sharing how much it meant when, fairly early in his career, Jack Nicklaus told him "You're a lot better than you think you are -- and when you believe that you're going to be tough to beat"...and Lee's low spinning wedges from 100 yards out and those amazingly consistent 'blocked' tee shots to the centre of the fairway, time and time and time again, which made Jack realize, during their showdowns, that Lee was never going to back down or beat himself
And of course, Jack himself, with those three amazing (Macgregor) 1 irons!, soaring majestic shots when it counted most that left other pros - the Weiskopfs and Crenshaws etc - speechless: the 1 iron at Baltusrol, 240 yards, uphill, into the wind; the 1 iron at Pebble, the wind whipping off the ocean, the ball stopping inches from the cup; and the 1 iron to the 15th in the 75 Masters, way up in the air and landing on that green as softly as a butterfly with sore feet.
Excuse the ramble, but it's to say: it seems that for the longest time the golfers who played the game best and often truly loved to play it all valued great 'shot-making' as the essence of the game, and most appreciated and envied it their colleagues. And I think that for *this* generation of great golfers (Tiger Woods first among them), it would be the same, i.e. they'd be very happy to re-focus the game on what makes it so fun and challenging and rewarding and such a life-long pursuit, i.e. shot-making.
Jim S is probably right that most of today's tour golfers, if forced to using only 7 clubs, would just tend to hit 'less' club a lot harder. But maybe some of them wouldn't...