The majority of people here who aren't happy with their chosen career obviously haven't set their expectations correctly before starting out.
If you want to earn a lot of money, then get into investment banking or start a tech company which will be one of a million in being successful.
The fact is that most careers have their good points and bad points and it is up to you to decide what is important to you in life. If it is money, status, a stable routine or changing the world, then flying may not be for you.
99.99999% of people out there are in jobs that they either do not have passion for or didn't plan on doing when they were a kid. They drifted along in life and somehow fell into the job because it was easy.... and then stayed in it because that was easy to. They have no passion.
I've worked in 12 countries throughout the world from an investment banker on Wall Street to teaching scuba in Greece - and for me flying is the best job of all. I work on average 4 days a week and only 5 hours on those days. The rest of the time belongs to me to run my own business, write a book, design my dream house or whatever tickles my fancy. People dream of that as a retirement. And I get paid to fly, my passion as a kid. What could beat that?
I'd also suggest that if you have a backup career you can make good money at, then that is the way to go. I think that one of the reasons why are a lot of pilots are unhappy (aside from being prima donnas) is that they don't have anything to fall back on, they are stuck and feel ultimately helpless. I'd also suggest to them, that is what most of the working world feels like and to stop feeling like a victim.
Determine why you want to fly, and base your decision around that. If it is money, or status, then maybe flying isn't for you.