I run my own businesses on functional programming languages (Haskell and Elm) almost exclusively.
100% of my income comes from the three software products I own, all primarily written in Haskell.
You're displaying a pretty amazing level of ignorance here.
NewBusinessMonitor[0] is a tool for marketing your products/services to businesses in the UK. This company is a bootstrapped SaaS, built and run by just me. It's been taking money for over a year.
Comparestack[1] is a price comparison platform. Our first product is Moneygains[2] — a way for residents of Northern Ireland to switch to a better deal on their home electricity. I'm building this with a partner — he's taking care of all the business stuff.
I have a third in the reinsurance space, and it has taken funding. I'm not going to talk about this one so much for the time being — it's still in stealth mode.
[0]: https://newbusinessmonitor.co.uk/