There's nothing wrong with joining the armed forces for the short term. I'm sure large numbers aren't thinking of much more than 3-6 years. Loads of people are only into the training. The recruiters know this, and I can't imagine that it would have any bearing whatsoever.
On the other hand, aversion to leadership isn't a good trait to manifest. Even if it's true, I wouldn't give any excuse to think twice, especially when armed forces jobs are fairly tight. In an emergency, anyone might have to take charge of a situation.