I'm with you. The company is paying you for your time and if learning a new task is what you're getting paid for, great. If they "punish" you for it, for example "now you have to stay late and finish your other work" or you get dinged for not meeting your regular metrics, then they're full of shit. But if the request is simply please take care of this thing because we don't have an expert to can, then you just do it. I don't get what the issue is. It's interesting new stuff you get to learn.

However to be honest, I am in management and I manage a team of engineers, and I expect to them to be flexible individuals. Sometimes they're doing technical drawings, sometimes new development, sometimes assembling prototypes with tweezers, sometimes they're learning new software, and sometimes they have to create renders for customer presentations. If any of them gave me shit about "not my responsibility" I'd be pretty pissed off because IMHO an engineer needs to be a flexible individual especially in a small company.