What an extreme reaction. Many people would not be able to parse it since they've never seen a number written in this way, but you immediately write them off as assholes. Wow.
You're still approaching this with the background knowledge of what this is. If you've never seen this, you can only guess, and there are a couple of options.
I've been terminally online for the better part of the last 2 decades, yet I've seen this way of writing for the first time only ~5 year ago or so, and I still remember simply not knowing what it is. The first reaction is that it's simply a typo - the author mistyped - the dot should have been a digit or perhaps not be there at all.