Since MITChris has already written on this, my opinion is pretty superfluous, but since it generalizes to other colleges as well, I will go ahead anyway. 
First-order effect of not joining NHS: None
Second-order effects: Is your reason for not joining NHS that the service activities that are required by your school for NHS take up too much time? If so, will that affect your Guidance Counselor’s opinion of you? Is it the case that you “can’t be bothered with service activities” and you would rather hone your Ultimate Frisbee skills or something similar? If so, maybe you should reconsider–actually helping other people is a worthwhile undertaking. Teamwork and athletics are valuable, but you may need to set priorities (not directed at college admission–this happens throughout life). If the NHS at your school only does cheesy service projects, and that’s the reason you don’t want to join, then maybe your could join and redirect their efforts. Or is it the case that you are involved in a research project and you are up pretty late all the time anyway? In that case, if you have the right ethos to participate in service projects and just truly do not have the time, because you prioritize the research experience, I’d say give NHS a miss.