Ok, I guess I will chip in here while I have a few minutes.
For medical school admissions and residency match lists, in short, yes, it is pointless to undertake a research position (project) and not publish. For gaining life experience and learning how to become a researcher, it is not. Gaining scientific understanding during your undergrad years will come in handy later in your life if you want to perform research down the road.
Why is it pointless to undertake research without a publication? Well, adcoms want to see performance rather than experience. Think of it as taking the MCAT. We all experience studying hardcore for the MCAT, but do adcoms give a damn? No, they judge you on your performance. Everything about admissions is a number game. Your GPA, your MCAT, your number of leadership activities, $$$ to nonprofit organizations, and yes # of publications (preferably first author).
What is the difference between an undergad who works in a lab 40 hours a week and has no publications to show for at graduation and one that works 3-4 hours a week during his or her junior year with no publications. Absolutely NOTHING (they are = in this game) in terms of med school admissions. No performance = no merit. No publication and you perish.
If there are two things that will really boost your application it is a first author publication and a high (34+) MCAT score. In this discussion, to adcoms your research is meaningless without a publication.