You are not your tools
Do you think of yourself as a Python programmer, or a Ruby programmer? Are you a front-end programmer, a back-end programmer? Emacs, vim, Sublime, or Visual Studio? Linux or macOS?
If you think of yourself as a Python programmer, if you identify yourself as an Emacs user, if you know you’re better than those vim-loving Ruby programmers: you’re doing yourself a disservice. You’re a worse programmer for it, and you’re harming your career.
Why? Because you are not your tools, and your tools shouldn’t define your skillset.
Your tools are not your skills
Ask a programmer to list their skills and more often than not you’ll get a list of technologies. But technologies are just a small set of the skills you need as a programmer.
You need to gather requirements.
You need to debug code.
You need to design user experiences.
You need to build abstractions.
You need to avoid security problems.
And so on and so forth.
None of these skills are technologies. And if you think your only skills are technologies you won’t notice the skills you don’t have. And if you don’t know what you’re missing, you won’t take the time to learn the skills that can make you truly productive and valuable.
Your tools are not your job
If you define yourself by your tools, you are limiting yourself to what jobs you can get.
First, because you won’t apply to those jobs.
Second, because you will market yourself based on tools, instead of all the other skills that might get you that job anyway.
(I’ve written elsewhere about how you can get a job with technologies you don’t know).
Your tools are not you
If your identity is tied up with your tools, you won’t listen to people who use different technologies. Some tools are better than others at certain tasks. Some tools are interchangeable. But an expert using a bad tool can often do more than a novice with a bad tool.
Spending your time fighting over which tool is better is a waste of your time. Instead, spend your time listening and learning from everyone, whatever tools they use: most skills will transfer just fine.
The technologies you use, the tools you build with, are just that: tools. Learn to use them, and learn to use them well. But always remember that those tools are there to serve you, you are not there to serve your tools.