It seems like you’re suggesting, that when you buy a yo-yo, there should be a drop down box of some sort (for example), so you can select your preferred bearing option to be shipped along with the yo-yo. I’m not sure if I read it as you intended it though. :-\
I don’t think it’s a bad idea for the customer, but it’s a bad idea for the manufacturer and the retailer. It’s mainly inefficient. The end price would change for each customer, depending on the bearing selected. For example, the guy who chooses a SPEC bearing will pay a lot less for the yo-yo, than the guy who chooses the Terrapin X ceramic bearing.
When you buy a new yo-yo, the trouble is, you can never be sure what bearing will play best in it, until you get it. You can tell what bearing you usually prefer, but with a yo-yo you haven’t tried yet, it can be a hit or miss. So, most times you’re not even informed enough to choose the best bearing for the yo-yo, because you haven’t tried the yo-yo. The point of having a choice, is so that you might end up more satisfied with the yo-yo. But, if you make a guess, and then don’t like the way the bearing plays in the yo-yo, it’s just another excuse to “exchange a bearing with the retailer,” or “complain to the manufacturer about their yo-yo.” At least when a manufacturer uses the bearing that they like, it means they have tested the yo-yo with that bearing, and they know how their yo-yo plays with that bearing installed.
Another problem is that a retailer would be forced to offer every single kind of bearing on the market. If they didn’t, there would be no point in selecting your own bearing. That’s a lot of bearings to keep in stock. And, while YoyoExpert has a wide selection of bearings, most other retailers do not offer that kind of selection. The larger retailers would be the only ones who could even work within a system like that, and it would be too much time and effort to keep it going, even for them. They would have a pile of damaged, dirty, used bearings that have been exchanged for a new ones. It sounds like a good way to take a loss.
I think business-wise a stock bearing is the way to go. It is more reliable, more cost-effective, more efficient for business, and most people don’t even care about the bearing anyway. I believe most people play their yo-yos stock, and those who swap out are in the minority. I play my yo-yos stock, for the most part. I keep plenty of spares around in case I get a dud. If I swapped out bearings in every yo-yo I have, the bearing would turn into a separate hobby altogether.
It’s not a bad idea from a customer perspective, and from that perspective, it’s a great idea. But, from a business perspective, it’s an extremely bad idea.