I also think there's a lot of "snob" value about parents wanting their kids to go to Uni, i.e. to boast "first in the family" etc. And by the same token, they don't want their little darlings to come home from work with dirty hands/clothes in the way that, say, a joiner, builder or plumber will come home.
But also, we've now had a few decades where you "Need" a degree to get jobs that previously didn't i.e. nursing, police, teachers, social workers, etc. etc., so there's a "fear factor" among parents that options are limited without a degree.
Finally, decent apprenticeship schemes are still too few and far between. Smaller firms and one man bands simply don't bother with them due to the cost, hassle, etc. and plenty of places (especially out in the regions) simply don't have big employers, so no firms offering apprenticeships. It's OK if you live somewhere near a big BNFL or BAE site or in a city with lots of offices, but in lots of places, there's neither, so moving away to Uni is the only viable option for a decent education.