I suppose our definition of "startup" differs. It seems a startup can only be a startup if it's attempting to solve a problem that requires significant upfront capital and scaling. I disagree with that view.
For me, a startup is a company exploring the solution to a problem. That can be a BIG problem and that requires significant scaling, or it can be a smaller problem. Once that solution is found, and can be replicated easily, it's no longer a startup.
The question is, how long can a startup be a startup? I'd argue that as soon as any scaling is involved, it's no longer a startup and it's just a business. Startup implies that it's the start. Lifestyle businesses and regular businesses can both be guilty of claiming to be a startup long after they've become "regular" businesses.
When it comes down to it, they're all just businesses, but it can be helpful to have terms to distinguish the scale of the business. If you feel that lifestyle businesses and lifestyle startups are diminishing the prestige of startups, then you're probably in business for the wrong reason. That smacks of too much ego and too little passion for solving the problems you should be solving.