Sure you and I never click on those boxes, or disable javascript on offending pages, but the majority of web users do not. Many people do stick in an e-mail address, even if it's a bulk mail/spam address. Still, some people put in an address they actually check. That tiny amount of people, generate revenue.
I mean really ... the problem is people. It's okay though, one day we'll go extinct .. or we'll colonise beyond our solar system .. or someone already did that 2nd part and we're just in a simulation of said creatures.
Sleep well.
If you have good content people will search hard for a way to get on your email list if necessary, i've done it before.
I ask, because that doesn't match up well with my (anecdotal) experience as an end user. When I'm searching for software to either replace something I'm currently using but dissatisfied with or when I'm doing something new (to me), I want to demo candidates so I can get a feel whether I like them or not. I don't mind paying for quality software (though much quality software is free), but requiring credit card info for even a demo is the exact sort of hurdle which I won't put up with. The cost (in time, and potentially wasted time in the future) is just too high.
[1] I'll fill out short "email, name, company (if optional), industry" form but only if I don't think some salesperson is going to give me a call.
For business purchases, the compliance and other risk is way too high for me to do that. You get knocked off the list if you require that.
Some companies don't want "users" they want paying customers. The article does not do a good job at all at explaining the context of their frustration other than "Ugh I don't like being treated like this, therefore other people don't, therefore it's bad".
I'd say the article is downright bad. It assumes there is only one use for a modal: abuse.