I think the point is you should always think if A is truly something you want to do, or if B is more interesting. I thought it was applicable to any field.

"If you're not interested in the field to the point of wanting to do it in your free time, then you should think twice" (not paraphrased) is generally NOT a bad advice / point.

It DOESN'T mean that if you are not "that kind of interested", then you shouldn't try in the first place, or should quit. You still can do it, and be very good at it if you worked for it, just like any other skills requiring field. You probably won't be the very best in the industry, but you absolutely don't need to be. Not everyone can be the next react inventor or something.

The point is that you should always think if A is the best option for you or if there is something else that would be more interesting to you. That is applicable to ANY field. Whatever happened to famous "find something you enjoy doing and make a career out of it"???

If despite not wanting to touch a computer outside of work, you are content (ir even enjoy) working and doing what you do, then there is absolutely no problem. If you are unhappy, then perhaps you should think about it again. That is my view.