Your example is a bit extreme, and it sounds like you are talking about you are talking about your own website which, with all due respect, I doubt anyone else is remotely invested in the success of, so you as a developer have an unusual degree of freedom to be this dismissive.

In the real world, anyone who is as dismissive as you is likely in a position where they’re going to have a boss telling them to pull their head in. The reality is the vast vast majority of users won’t know have a clue how ‘disrespectful’ the browser extension they’ve installed is of ‘the wishes of the developer’ or whatever, and a poor customer experience is a poor customer experience, no matter whose “fault” it is.