Not sure why you say this is dead wrong? It just stresses that focusing on only language is leaving a lot of opportunity on the table.

Of course, make sure you have a business in your primary customers' language, I agree!

It may be leaving lots of opportunity on the table but at the early stages of a company - which includes many in the Hacker News community - they're not taking advantage of the opportunities that are already in front of them.. or they're still figuring out how.

Adding an additional market at that stage ranges from a waste of time/money (if it doesn't work) to a poor customer experience (if it does). How do you sell to and support a customer if you don't speak their language?*

This is not a decision you want to make lightly without some deliberate thought and planning with the rest of your organization.

* I work for Clarify.io which although we don't do translation services (and no interest in it), we work with multiple languages on a daily basis. Adding support in even one language the founders don't know is challenging at best. Luckily, between our two founders, we have 5 languages.