Yup, people stuck on optimising (or overthinking which datastore to use) before actually having a business are missing the point.
The worst code I worked with was at travel agency startup and they are REALLY successful now. It was REALLY REALLY bad and hard to maintain. The owner of the business just said: well, bugs happen. But when a customer (not too many of course) encounters one, they probably call the helpdesk. Sounds stupid, worked great, business wise.
4 years later, I am sure they still have problems with the crappy code, but the business is fine!