What's the point of points ? For many people they are for fun. The more points you acquire the better the goodies you can "purchase" for yourself or your Spark Friends. I give spark goodies all the time. can't do that without points.
Also, many members do use them as incentive to complete challenges or goals during the day. Example, you can aquire points by drinking 8 glasses of water or taking a 30 minute walk.
Some members do take points a little too seriously, it happens. Most time they really are just for fun. You could totally ignore them if you'd like.