The problem is that trying a language isn't like trying a new restaurant. At a new restaurant, I'll know within an hour almost all I would know after a year, and my chances of misjudging the restaurant that first hour are both low ("Hmm, none of these dishes taste very good to me, and I'm not wrong about that") and of minimal consequence (maybe there are better dishes I missed, or not, but I can just try a different new restaurant tomorrow.)

But my first project in a new language will take more than an hour (well, "hello, world", but that won't be enough of a test), and after I find something I don't like about the language in a first project, I've either found something bad about the language or something bad about me that this language is going to cure. Which is it? How will I know without an even bigger project...and pretty soon I'm the OP having spent a year giving the language a fair trial and now needing to start over with another language for another year.

I have a lot more hours left to investigate restaurants than years to investigate languages.

So, it's not a question of "fashion" per se, but trying to learn from the experiences of others. Of course, "others" vary, but you can still learn a lot about things that wouldn't be obvious to you in a first project by reading a lot of those varied opinions.

I read a lot about Go that interests me, but I just saw a survey of several thousand back-end mobile developers that showed that now, after several years of availability and the Google connection and all the talk about being a better Python and its explicit positioning as optimized for server-side apps, Go was not among the Top 8 most used languages for server-side apps. That interests me, too.