"Do you realise that the term "alt-right" came into existence to hide the blatantly white supremacist leanings of its adherents?"

It just means alternative right.  There's no monopoly on the usage of the term and it's not a copyrighted or trademarked phrase. 

Yes, a pack of white supremacists out of Whitefish, MO, where there's been issues with neo-Nazi groups for decades, took the term and started a website back in 2011 under that name, but that website's effectively defunct. They've moved on to the "Daily Stormer" as their site of choice. It's clear that the term has been appropriated and repurposed by entirely different groups, now, and is much more mainstream.

Breitbart's used it, and they are an almost completely Jewish owned and run news agency with offices in LA, London and Jerusalem. Pretty hard to argue that a bunch of Jewish reporters, editors and executives are really neo-Nazis in disguise.