Being as popular as it is, it is everyone's choice and so maintains its profitability and will be the go-to game for a long time.
The amount of literature devoted to the game gives it a big advantage over other less popular types. It is the most studied of games and it is even possible for the most studious of players to learn much from the published material. This renders decision-making that much easier.
These advantages of accessibility and the copious available literature surrounding limit hold'em means that there are a lot of skillful players in the game. This fact can unfortunately make the game less profitable for the average player. The average player can expect enjoyment of the game but no profits.
For you, who are determined to not be just an average player, you must do some soul searching to discover the game that best suits you. You know that poker is a game of chance of course, but it is also a game of skill, creativity and resourcefulness. It requires a tolerance for risk and a high degree of self control. You must find in your soul searching as accurately as you possibly can your tolerance for risk-taking and how you behave when you encounter it. Can you control yourself or do you run amok with impetuosity and careless behavior? Do you take uncalculated stabs at chance or do you carefully calculate the risk and either stop yourself or go ahead and enjoy the thrill if the odds are in your favor?
Once you have your risk level determined, if you find that you are the impulsive type, stay with the cup of quarters and the slot machines. If risk for you is something to be avoided, go on and play limit games - low limit for the most risk-averse, higher limits in proportion to your level of comfort at higher risks along the scale.
Rigid logic is not the same as psychological insight. If you think that you like to have things under control as much as possible, decide whether you are best at calculating the best card combination in relation to every other combination that has been played so far in the three-hour long game, or whether you make your best moves by reading your opponents' current hands and tells by observing their expressions and body language. For the latter type of player, no-limit and MTT poker is probably best.
Interestingly, it is also the latter type of player who has the best shot at developing as a player. High-limit games are rare. High risks are also not likely to lead very far. No-limit and tournaments offer both accessible and complex poker challenges, providing the best environment for aspiring beginners.