.Jesus Tap Dancing Christ on a damned cracker are the FOSSies on this site so dang ignorant that they are actually gonna bitch that when A NEW OS IS INSTALLED it actually gives you a motherfucking way to boot the damned thing? Really? Does Grub ask if you wanna keep the Windows bootloader?
Pretty much every distro installer I've used asks whether you want to install the bootloader, and to which drives (usually right after the partitioning step).
The Windows installer doesn't give you a choice - it just overwrites the boot sector on C:, which makes restoring the original bootloader a pain.
The complaint is not that Windows installs a bootloader, it's that there is no way to prevent it from doing so. It's also worth noting it hasn't been just a consumer OS since XP - it's also an enterprise OS and the ability to load things like RAID drivers during the installation reflects that.