[jka]

> If a software does what you expect it to do and does it well but includes a few prompts here and there for marketing purposes...is that really so bad?

As the article mentions, the problem generally isn't any one individual change - the concern is about the sense of direction for the overall project. The typical direction is from "simple software that helps people to achieve some goals" towards "product with features designed to increase revenue, data gathering, and stickiness" -- like the login-required anti-feature mentioned.

If those changes are gradual then users may not really notice the small differences as they introduced, and if anyone does complain, it becomes easy for supporters of the project to deflect complaints (as, arguably, you may be here -- not ostensibly trying to keep the author with the product, but trying to reduce their credibility and persuade others that there is no problem).

In many cases, free and open source software can help avoid a project falling into dark patterns because it's possible for people who disagree to fork it and maintain/promote their own alternative -- and then for other people to compare the original and the fork on their merits (which are transparent).