I agree and have removed that page. I should have removed it sooner and apologise for the inconvenience.
I tried to support Mono for many years but it never in those years really was reliable enough for important production sites and it was a lot of extra work trying to support it. Back when Mono was under Novell they used to put out a VMWare image of opensuse with mono for every new release of Mono and that made it easier for me to do testing as I'm not a linux super guru. But they no longer provide such and it makes it even more work to setup a test environment. I always had to make separate builds for Mono and the last version of mojoPortal where I did that was version 18.104.22.168 which can still be downloaded but I have no idea if it works with the latest mono. Its hard also to keep supporting it because only a very old version of AjaxControlToolkit works with Mono as far as I know.
My perception is that the Mono guys are more focused on mobile these days and maybe web services to support mobile, but large complex web apps are a difficult challenge, they don't run their own sites on Mono, they use php. Its hard to have confidence in their web stack if they don't eat their own cooking.