I disagree that adblockers are theft and that the comparison is accurate.
Stores do indeed account for a small amount of theft in their budget in the way of security and special procedures, and also for actual theft. Precautions are taken, security personnel and procedures are evaluated, and there's a cost/benefit analysis on such situations. Living abroad in certain countries, it's no unusual to see even a small corner shop have a prominently displayed security personnel standing at the front just keeping an eye on things on top of an array of security cameras across the store. It's a cost of business that physical stores take, and it has an impact on their public perception, and that's a choice the store owners have to make; public perception, or the cost of theft. If websites feel that strongly about ads, then they should make it clear - an adblocker is an indication that people don't want ads. The reason could be as simple as "they're annoying" to "they're intrusive privacy wrecking tools of the devil", but it's a response to the complaint "these ads are annoying." Advertisers have very simple and low cost solutions to this; they can ask for whitelisting, they can ask to turn off the adblocker, they can use the adspace that is blocked to offer an ad-free alternative, or they can just not serve the page, something I wish more would do. Yes, such a position may harm the websites readership, but it's better than the alternative.
As for it being theft, I disagree as ads on a website are basically a unilateral agreement that I have no agency in. Making it a condition for viewing the site, whether it's a spoken or unspoken contract, means that we are in some sort of arrangement - your content for my eyeballs and privacy. I don't know what's on your page before I load it, and titles being what they are for articles, it's even harder to know if it's something I want to see. A single paragraph summary of an AP posting isn't really worth me disabling the adblocker. A conspiracy theory style rant on such a posting isn't worth my time either, regardless of the agenda. A list that is basically just copy/pasted from wikihow with some stock photos added isn't worth it, and so on. If the requirement for your page is I must watch ads, then politely let me know before you spam me with ads so I can make the decision as to whether I want to view the content or not. I have the adblocker on because I specifically don't want ads; the risk outweighs the reward in most cases. If the site operators feel that I shouldn't see the content with an adblocker on, I'm fine with that. That's their offer, and I respect their wishes. I just want website operators and advertisers to respect my wishes instead of trying to circumvent it, or flat out lie to me about why they want me to unblock ads. I don't have an obligation to view ads because I clicked on a link that I had no idea of the contents of. The agreement between an advertiser and a site isn't any of my business, and if they want to make it my business, that's fine, but they need to be upfront about it. Removing my agency in the matter is not a way to win me over as a repeat visitor.