I for one am also left sad by this, I currently have the app installed on my Linux desktop and guess I will be uninstalling it now. I honestly wish it was easier to get the Windows version of Vortex running through things like Wine, but it just has too many dependencies from Windows that just don't play well under Wine.
Sure there are other ways to get games like Fallout New Vegas or Fallout 4 to use mods under Linux, the most straight forward way is to just use the games own built in method for loading mods, or in the case of other games like my current favorite, Unturned and RimWorld, they just use the Steam Workshop. But once you try to venture out to other games that dont have such a straight forward to load mods, or in the case of Bethesda games, if you try to really push the limits of just how many mods you can load in, using a tool like the old Nexus Mod Manager, or with its newer Vortex, having something that puts more effort into maintaining that load order was really helpful.
But yah there are other apps for managing mod load orders, some like the ones built for games like Fallout 3 are pretty old, but it looks like people here have mentioned other options so I will have to keep my eye out.