You are not a shopkeeper being extorted for protection money, you are a (unwelcome) shop customer demanding things you don't want to pay for while being free to go to another place.
Except the timeshare pitch is hyper-personalized specifically for you based on your entire internet history everywhere and is designed to yield the maximum chance of manipulating you into falling for it.
As a consumer you have easy options to block out the sales pitch, except the store who has a monopoly on the thing you want is now trying to scare users into disabling their ad blockers. The users that do this are disproportionately more likely to be less versed in how these things work and are thus more likely to fall for the scam.
Yes, it's a protection racket. It's just got a funny hat on this time.