It’s because not everyone’s use case is the same. One of the reasons why I moved away from password managers like 1Password is that they don’t listen and it’s their way or the highway. At least Bitwarden will listen and let us vote on features.
I have a few people I know who need this feature and would not use a password manager without it. Having this feature is better than them reusing passwords. Plus, this feature is not on by default and a warning is given so why not keep it?
I also feel this issue has been blown out of proportion. It is an issue, but people act like there is code injected into Twitter and it can steal your bank password. This is not true, the extension will only fill based on the Browser and not the contents in the page. You also have the browser protecting you from such attacks, this is why Chrome or Firefox has no issue with auto-filling passwords.
Everyone’s threat level and use cases are different. The fact that Bitwarden gives us so many options to suit our needs is what makes it so great.