A few years ago, a friend went to a ground fighting tournament, and told me about the challenge he had with one particular opponent. This person started the match sitting down, legs spread apart, and waiting for an incoming attack. It was effective strategy at this tournament. My friend was unable to engage without getting entirely wrapped up. Hearing about this left me feeling disgusted, but it took me a while to figure out why.
I eventually realized that it was because my goals did not align with the goals of this other person. I'm interested in the self defense aspect of the martial arts. To me, sparring and tournaments are useful insofar as they develop and measure skills that can be used in a self defense situation. While I recognize the need for rules to keep these activities safe, I worry that they might result in a blind spot that could prove fatal in a confrontation on the street. I combat this tendency by mixing things up, moving from one type of practice to another, focusing on the attributes I'm trying to develop, and keeping a healthy distance from any technique that depends on a particular set of rules.
Of course, this is the exact opposite of what you should do if your goal is to win tournaments. My friend's opponent was relying on the fact that he couldn't be kicked in the face, and as a result had developed a position that gave him quick control of a grappling situation. Muhammed Ali famously leveraged the "rope-a-dope" technique to defeat George Foreman, taking advantage of the very specialized terrain of a boxing ring and the fact that kicks and strikes to the groin are not allowed. Many Tae Kwon Do practitioners will execute a quick series of kicks and then move in for a clinch, waiting for the referee to separate them, safe in the knowledge that throws, knees and elbow strikes are out of bounds.
None of these things are "wrong", as long as your goal is truly to learn to win tournaments. Where I get concerned is when people begin to spend their things unrelated to, or perhaps even contradictory to, their real goals. Perhaps they saw something neat on youtube and never thought about the context and utility of that particular move. Or, much more insidious, they might be imitating a more senior student who has a different set of goals.
This can be an even more difficult syndrome to avoid when it comes to intensity, rather than techniques. A lot of people practice martial arts for a little exercise and the comradeship. Going through the motions in a half-hearted way is just fine for them. But if that's not your goal, it can be really hard to constantly push yourself to the breaking point when nobody else is doing it. The pressure to conform can be hard to avoid, even for adults.
You don't need to have exactly identical goals to everybody else in your school. But it helps to remind yourself periodically what your goals are, and make sure you're moving in the right direction. As they say, if you keep traveling in your current direction, there's a terrible danger that you'll arrive at your destination. Make sure that destination is yours, not somebody else's.