Despite being an ECE major, I didn’t really bother doing anything with Linux until two things happened at the same time:
I started having to work in several different build environments that were just easier to set up in Linux
I started running Minecraft servers/doing server modding (starting back in the days of Hey0’s server mod and carrying up through Bukkit).
I wouldn’t call myself an evangelist at all. If you’re doing something that I think will be specifically easier to do in Linux (mostly servers and specific kinds of software development), I’ll point out how… but I find that a lot of people’s advice on “use Linux and X FOSS tool” ends up being akin to giving someone bike shopping advice on which welding torch to use to construct their bicycle frame.