I would not discourage my son, but he is only 5 so we will see in 10 or 20 years how things are going.
I would never push him into anything, but maybe suggest career paths that I think might interest him depending on what he likes/dislikes during high school.
I still think engineering, for the most part, is a stable career, and this from an automotive engineer in MI

Although, I do think some fields are much better than others. I would help him weigh the time/money spent in school vs. future potential/happiness etc.
Personally, I am not a big believer in the do what makes you happy, as I would be unhappy when I got home because I would have half the fun money, but I hope my son can have the best of both worlds and be happy, and make money. Don't get me wrong though, I do need to feel a sense of accomplishment in my job, have challenges, and be a part of something

Maybe what I ma trying to say is, I don't need to be happy, just not unhappy.