Slugger,
Kudos to you for having goals and aspirations. Keep working hard and you'll see those become reality, whatever they may be.
That being said, nobody can predict where the industry will be in the 6 or so years between now and when you have a college degree and competetive times. This industry is very dynamic. Last year at this time, the airline I was working for anticipated hiring over 1000 pilots to meet the needs of new growth and people leaving for the majors. By September, the 200 or so hired in 2008 were furloughed.
As for your dad, yeah there is some validity to his comment. However I challenge you to find any career path that hasn't lost some of its luster in recent years. I also challenge him to find any career that gives you as much time off as this one does.
Back to the goals. Never lose sight of them but keep them in the background. In the meantime, enjoy being 16. Savor the flying you're doing now and the achievements that are coming with every lesson. While it's a neat way to pay the bills, sooner or later it becomes like every other job.