I certainly wouldn't say it's "a lot" of Android users. The only people I've ever known who have used oversized batteries have also had rooted phones running some alternative Android distro - hardly your "typical" user. Most average Android users don't know oversized batteries exist.
And like it or not, most new Android phones don't even have replaceable batteries, so the number of users with oversized batteries is getting smaller and smaller.
And like it or not, most new Android phones don't even have replaceable batteries, so the number of users with oversized batteries is getting smaller and smaller.