I think there's some very good advice in Phil Barone's post. I've felt both sides of the argument personally.
As someone who now works in a shop with 100's of mouthpieces, you'd think I'd always be changing. Not really true. I've been on the same Meyer 7 on alto for the past 20 years. On tenor, I've switched a few times, but I generally try not to switch too often, and at least give a piece 6 months to settle in on. That being said, I love trying stuff! It's fun, and gives me some perspective on what's out there, and what is good.
That being said, I've had some legendary players stop by the shop, and it's about 50/50 on if they are gear heads or not, and both ends of that spectrum have amazing players. Bob Mintzer was one that has switched a couple of times, but was pretty adamantly not a gear head ,and didn't want to even mess with it. Joel Frahm, on the other hand, spent about 6 hours trying every tenor mouthpiece in the shop. He sounded incredible on each and every one of them, but he was always searching for something better, and ended up buying an EB Link we had at the time. I'm guessing he's moved on to something else since then. That's not a dig on Joel either...quite the contrary. He was SO good, and so inspiring to hear play, and if he wants to be a gear head, who am I to dissuade him?
Now...it's totally different when I get a high-school or college player in. Then, I'm helping them find a good fit, but preaching the gospel of "don't come back in two weeks looking for the next one". At that point in a player's development, I'd encourage them to learn the mouthpiece inside and out and know exactly what it can and cannot do. I think it could actually harm their development, by having them focus on many mouthpieces rather than good old fashioned shedding. In this situation, I absolutely agree with Phil.
For hobbyists, I'd say - do what you want. If it's fun to buy a bunch of mouthpieces, more power to you! You are doing it because you love it, and don't let anyone tell you you can't have fun trying lots of mouthpiece options. As long as you don't see it as necessary, what's the harm?