Well said, and I could claim some guilt in years past about jumping on the next big thing and encouraging my network to learn what seemed to be on the horizon. I still keep track of trends and will mention them to candidates, but I now try to tell engineers (particularly younger ones) that they should try to experience several languages and tools to become better at the overall craft. Deep engineering experience seems to be acquired by seeing variety.

I think the fanboy comment would be attributed to someone today walking into an interview and saying they 'only want to work in (specific language)', which would be a turnoff to most companies. Having passion for a technology is good and engineers will always have preferences, but being willing to help out where you can will have greater value.