Sorry to hear that. It's a tough situation. I've been in a similar fix with an iOS dev. We tried to work with him for way too long before scrapping everything and starting over with new people. It just ended up delaying the process even further because we wasted so much time trying to make it work with him. The client shouldn't be paying in time/money for the outsourcing company's learning curve. It's hard to walk away from a sunk cost, but it's the future benefit that you should be concerned about. It sounds like you aren't going to get anywhere with the current team. I think the founder should start looking for someone new.

In the meantime, the founder should take a couple of web development courses. There are some great Intro classes through Skillshare, Codecademy, etc. It will definitely help him in the long term if he is planning on running a tech startup.