Has nothing to do with weight, (I ride a ZX7R and prefer its weight afterall) has everything to do with the fact that they are expensive as fuck to replace, dont last forever, and attempting to remove them causes you to get a trouble code.
If you are always buying bikes new, and dont keep them more than a few years it is never a problem. For the rest of us who buy used those things are a giant pain in the ass.
Someone was telling me about how the ones in vettes dont have replaceable batteries, and you have to buy new units. And you have to, because the cars wont pass emissions due to the check engine light being on. And they cost a couple hundred a piece.
Not to mention they are unreliable, inaccurate, and make balancing the wheels a pain.