You can prove them wrong as many times as you want and if your language isn't spelled J-A-V-A or C-# then it doesn't matter how many 9s of uptime you can easily achieve or how much scalability you get for free to them. They've already discounted it in their minds and they're just using industry bullshit-speak to explain it.

I would love to punch Hani Suleiman in the face.