I didn't realise that Samsung actually sold more phones than Apple (I've just looked at the numbers and you're right). Apple's smaller set of devices does help them a little but there isn't a lot to choose there.
I think my overall point is still valid because I have had Samsung phones for a while and have found their Bluetooth to be pretty good. This is not surprising as Samsung actually bought one of the biggest Bluetooth chip vendors (CSR) at one point, so they do have control over the full stack.
Samsung bought what was advertised as mobile handset business after CSR failed to spot that combo BT/Wifi chips were the future and threw away their lead. Qualcomm got the rest a few years later.
("what was advertised as" because there wasn't really a differentiation in the R&D bits, so there was a somewhat arbitrary split and hasty redacting of repos given to Samsung to avoid names of other customers in comments).
Samsung's phone division and electronic parts division aren't the same thing, so there was no guarantee that the phones would buy the Bluetooth/Wifi from their new acquisition, although I hear they did eventually.
I think my overall point is still valid because I have had Samsung phones for a while and have found their Bluetooth to be pretty good. This is not surprising as Samsung actually bought one of the biggest Bluetooth chip vendors (CSR) at one point, so they do have control over the full stack.