I'm not sure I follow. How can getting (for free) a long list of people who may be interested in the product once it launches be a bad thing?
I think the OP's main point is that instead of having a landing page you should be concentrating on product/market fit by describing the product. I think startups with these coming soon pages are already doing that, just not on their public website.
I think the OP's main point is that instead of having a landing page you should be concentrating on product/market fit by describing the product. I think startups with these coming soon pages are already doing that, just not on their public website.