You actually have a point there, some newbies may not understand the implications of having more SP.
In the simplest term, having more SP will give you more power on the platform. For example, when you curate, your upvote value will be greater, you will get more curation rewards, ie more SP that you can then power up. So it's a circle that helps you to grow.

I see a lot of good-hearted people here who host contests all the time but not always a lot of entrants which is a shame. I would say, if you see any contest with Steem/ SBD/SP/upvote as a prize, do try to enter. You really have nothing to lose and you may gain some new followers!!!

!engage 20