There could be tons of reasons on why you would score badly in your younger years. That shouldn't mean that you should be excluded from a chance to college IMO.

I performed pretty badly before my high school (gymnasium) but after that I performed well as I found what I was interested in. But I didn't have like the best scores but I still have a good education in IT and works as a competent programmer today.

Perhaps I wouldn't be as successful if college weren't free in my country. It's just stupid not to offer college for free. A less educated population leads to bad things. Just see who the US president is.