I started with Flask because I knew some Python. I just moved to node.js / Meteor. I wish I had started with the latter. I wish someone had told me "Python is nice, I understand that you're enjoying it right now, but learn these JS web frameworks." Anything else is a real disservice to beginners.

Said no one ever.

This is just plain wrong to force someone with your new hype and vague idea of how a web application should be developed using only your new hipster framework of choice and nothing else.

There are tons of way you can write a web application, that's why open source is cool, chose the one that pleases you and have fun with it, but stop trying to prevent others using anything else but what you judge to be the best.

I'm the complete opposite you are entitled to your own opinion but I started with node.js / Meteor, I moved to Flask, and learned Python, and I've never looked back.

I have strong opinion (you might disagree with me) that Javascript should stay in the browser, like it was designed for, and inherited to browsers to this very day.