That could be part of the reason yes. Other part could be ur decent at tactics but lacking in other area's and that's why ur rating isn't higher. Just a thought. :-)
Tactics Trainer rating?
You are having a big misunderstanding of what your tactics trainer rating means. The rating is just a tool to track your progress at tactics training.
You could have a 2500 rating at tactics trainer and have literally no idea how to conduct a game of chess. There is a lot more to chess than seeing combinations.
I have noticed that my online-and live chess ratings are much lower than my Tacitcs Trainer rating. Why? Shouldn't they be equal? Or am I not the only one to experience it? In TT my top rating was around 1900, but I can never play such strongly. Can the problem be that in TT I know that there's a trick in the position, while in a game I don't always look for it?