It can suggest that you don't care much about the future, or that you aren't very ambitious. It is wise to apply to schools that have faculty with interests that fit with your own. Do your homework. Go to the library and look up the publications of the faculty. Decide whether this kind of work is what you want to do.
Many schools admit students into specific labs.
That is, each faculty member will admit x number of students. You should know that person's research program. If it fits what you want, say so, but do so after you have carefully researched the matter or you will inevitable appear unsophisticated or even manipulative. Other things that may go in your statement of interests are research, applied and professional experiences and relevant skills such as computing skills. Letters of Recommendation Letters of recommendation are extremely important.