1. Folks spear-heading the Noise Protocol Framework (upon which Signal's protocol is based) are cryptographers [0].
2. They built upon existing standards for one specific purpose: Creating two-way secure channels [1].
At some point in time, all now well-established cryptographers will have developed their first own cryptosystem, without already having established a good reputation. Whether or not someone develops a cryptosystem without being famous for cryptography work is simply not a good argument for discussing a cryptosystem. The properties of a cryptosystem are a good argument for discussing it.
(the criticisms are well enough known that people either aren't going to listen or can just go read them)
It’s almost as if your cognitive time series is not the same as everyone’s.
(why the parens)?
Don't get me wrong, the Telegram crypto can (and should) definitely be criticized. But please criticize that they use "bad crypto" or "strange crypto" or "unreviewed crypto", not that it's their own. (And of course, substantiate such claims with references that can be discussed.)