Ask HN: What is your opinion on Fake Door Testing?

What do you think about Fake Door Testing? Is is a valid strategy to quickly validate ideas or do you find it dishonest?

For those who don't know what it is, here is an example scenario: You want to implement a new feature, but even the MVP will take +3 months to implement. So instead, you make a minimum UI without any business logic and when the users click on the button you tell them "coming soon" and then you test how many people wanted to interact with the feature and if it is worth it.