> Python is slow though, and for many use cases it won't work.

This is actually the only criticism from the article i think is invalid.

Very little in the business world is so performance sensitive that language (as oppossed to algorithms used) make a difference.

If it does make a difference, python is still probably fine for the prototype.

If its still an issue, just use another language. You are at the beginning of the project, its trivial at this stage to switch languages.

All the other criticisms i consider very valid. The language choice example is a stupid one.