im only wonder, if you do hate so much carrier bloatware, why do you keep buying them?? i live in eu, and all my stuff is free from carriers. i would never buy a phone stuffed by a carrier or tied up...
and yes, they go back and forth between carriers, google and manufacturer before you get an ota update.. basicly, it is all up to you. if you allow, they will surely use it... most people probably just dont care, so you cant do much more than complain.. sadly..
If you live in North America, you will find that for most people, it is not obvious how you can buy a phone without any carrier bloat and unlocked. They make it very easy and attractive to people to buy carrier branded phones. Since you don't live in North America, I'll explain what it is like in Canada.
If you go to a mall or any shopping area, you will find a lot of carrier stores. The main ones in Canada are Rogers, Bell and Telus. If you know little or nothing about buying a phone, the easiest thing for you to do is just go to one of these stores where they display a bunch of phones and buy one. All of these phones have carrier bloat and are locked ot the carrier.
Now, there are also other mobile or electronic stores like Wireless Wave and Best Buy. They display a bunch of phones. However, if you will find that almost all of these phones have carrier bloat and are locked to a carrier. The last time I checked, the only unlocked phones are the ones that suck and are very old.
The carrier locked phones are also heavily subsidised. You will find them to be hundreds of dollars cheaper if you buy them on contract. For phones that are several hundred dollars, it is very attractive to get them on contract with the carrier. Phones on contract will have carrier bloat and will be locked to the carrier.
If you look at all of the advertising, it is extremely rare to see an ad for a phone plan without the cost of the phone. You really have to search and ask for plans where you bring your own phone.
For most people, the main channels where you would typically buy a phone do not have options to get a phone that is unlocked, let alone have no carrier bloat. The cost of getting a phone on contract is very attractive compared to buying one outright. For these reasons, many people just get phones with carrier bloat on contract.