We do both. We save ~18% for retirement (depends upon the year, some years 15%, some up to 22%). We are 48 and 53 right now, DS is 8. We started saving for retirement in our early 20s, long before having a (single) child. We do not save a specific percentage for college, but are on track with savings for him to be able to attend a private college in 10 years, if that is what he elects. We would like to retire when he finishes college.
I do not see that simply hoping the college model will change in the next 10-15 years is a realistic way to prepare for college. Skills and experience are NOT more important than a college diploma (and an actual college education). According to all the most recent research, college graduates earn 60% more than non-graduates, have a way lower unemployment rate, have substantially greater lifetime earnings (adjusted for the time cost of money they laid out for college and their fewer years of earning because they are in school) AND they are HAPPIER. Yes, there are always questions when studies try to measure happiness. But I think it is hard to beat richer and happier both.
I think our ability to save enough money has a number of bases. First, our parents provided both of us with the education (and professional school) that has enabled us to have steady, reliable and rewarding (financially and professionally) careers. For this we are both grateful. It enables us to provide for ourselves, our child and our employees.
BOTH of us work. While I have no problem that many people choose to be stay at home parents, that is a financial sacrifice (of our futures and our son's education) that neither one of us was prepared to make.
We have chosen to have a single child - for lots of reasons - but not least was our choice to be able to provide one child with everything we hope for him to have to the best of our abilities.
We are not big spenders. We bought less than 1/2 the house our income qualified us for (according to the mortgage companies). We took a 15 year loan and paid it of in 11 years. We do not take a lot of vacations - when we travel it is generally for work or to visit family. We cook rather than purchase pre-made and processed foods.
ETA- How can saving for college and then NOT needing the money for college (because child gets scholarship, elects trade school, etc) be bad?. It's like you get a couple hundred thousand extra to apply to retirement. How is that bad?
ETA - We save for college just like we save other money - we invest in a variety of options. We mentally look at some of the $$ as destined for college. We have not (yet) put money into an account that would only qualify for college (certainly not one that only paid towards an in state school). So no penalties if we use the $$ for something else.
ETA - It is truly disheartening that so many people seem to see college as simply preparation for a job. And see an Arts degree or a kid going to school without a job path in mind as a waste of time. I want to send my son to college for the education. It's gravy that he will also be much more financially secure for life because of it. Education, science and the arts are not a waste of time. They are a HUGE part of what civilization, history and the future are about. OK, done with the soap box for now.