From the manufacturer's perspective.
Lets double that number. we could stick 3 drivers in the bag; one with extra draw; another with more loft and another just for show. We could have 3 fairway woods, 3 hybrids and a driving iron. Add to this all the irons from 1 thru to 9 and then 5 wedges - 48°, 52°, 56°, 60° & 64°. That leaves enough room for a couple of chipping irons and a prile of putters. Callaway, TaylorMade et al would be licking their chops and I bet plenty of golfers would go for it.
Would golfers play better with double the choice? Noooo! I find that the opposite is closer to the truth.
For the good of the game.
Lets leave the present rule alone for the pros. They have put in the hours and can float a 9 iron consistently to 140 and an 8 to 150 and so on. I know very few normal golfers who do this with any consistency.
I personally play with 7 clubs in my bag and I can shoot around par with them. When i go out with 14 clubs I normally play worse because I often choose the wrong club. I have a driver for my tee shots; 5 wood for 170 plus tee shots and longer fairway shots; 5 hybrid for all shots 150-170; 7 iron for 130-150; 9 iron for all shots from off the green to 130; 56° wedge for sand and when I have to go high and finally my putter. With this selection I rarely choose the wrong club.
I would change the rule for amateurs. I am not a lover of the handicap system but I know its there and its probably there to stay. It does however make this new rule easier to apply. It goes like this...
Class (1) Handicap 4.4 or lower may use up to 9 clubs.
Class (2) Handicap 4.5 to 11.4 may use up to 8 clubs.
Class (3) Handicap 11.5 to 18.4 may use up to 7 clubs.
Class (4) Handicap 18.5 to 25.4 may use up to 6 clubs.
Class (5) Handicap 25.5 or higher may use up to 5 clubs.
I do this with many of my students and they get to class 1, 2 and 3 very quickly. When I play with class 4 and 5, I restrict myself to one club, my 9 iron and usually play bogey golf with it (and yes I do putt out with it). I can guide most of my students to bogey golf with 5 clubs but when they go out with more it all goes sideways.
We don't have a putter for 10 ft and another for 20ft, we use a thing called touch. I chip anything from 5 to 40 yds with my 9 iron using the same skill, and can use this skill to vary the distance with any of my 7 clubs.
Want to get down to a lower handicap, then get to know 5 clubs inside out before you pop another one in the bag.
P.S. I love playing with only my 9 iron and it gives me plenty of challenge to play bogey golf. It also improves my creative skills which add a new dimention to my game.