Yes and no. The problem is that most of the time the train of thought goes something like:

* we already have a working product

* we might aswell just add the features and visual polish we need and then launch as soon as possible

* we have too much work to do to rewrite it

* we can't refactor effectively because automated tests are mostly missing

This results in the project becoming increasingly burdened with technical debt, where it becomes impossible to add new features without breaking something. The next step after this is usually a rewrite (which, given the low quality of developers already in the company, since nobody sane will work on such bad code, is also likely to fail, unless IT is restaffed completely).

If the prototype is binned outright and the rewrite happens at the very start, I imagine that this can be avoided. Again, the trap here is that if the founder learned to write code in 6-12 months then they will be in that cute phase where they think that programming is easy and will not realise this.

In short, having a senior developer on board (at the very least as a consultant) from the very start appears to be mandatory for long term success and minimisation of headaches. It's just what I've seen in the real world. Companies which went for quality from the very start grew rapidly. Those which attempted to minimise development costs at the expense of quality did not reach the heights.