It takes roughly twenty-five years for a new idea to catch on in medicine (or for the medical community to catch up to what is already generally known!). This is the time required for it to be tested in the vessel of "science" and become accepted as official policy. Often, many years before this happens the general community comes to realize that the testing/research was wrong! Remember, just because "everyone" says something, that does not make it true! This is a prime example--the research has been available for YEARS supporting the fact that it's not sun exposure causing cancer, it's the chemicals in sunscreen!
The countries where skin cancer rates are highest are the ones that advocate sunscreen use the most!
Be smart about exposure, don't burn! But it's all about moderation, and avoiding the sun out of fear of skin cancer is the absolute wrong thing to do!