dotNET will stay around just like the mainframes but it’s not a growth market nor the worldwide norm for enterprise web backends.
I work on legacy platforms so I know there is good money in dead technology. But that don’t make it the future.
I just don’t see any legacy codebase being rewritten as dotNET and a similar amount of new greenfield dotNET projects as new Perl project being launched due to NETs heritage as a windows component.