And do whatever works for you! I see index investing being most beneficial for people who don't have time to do their own research or who don't have the skillset to judge the fair value of a company (a ridiculously difficult feat).
Investors who are more informed about the financial markets will gravitate towards active investing, which is fine. I may join active investing one day, when my registered accounts are maxed out. For now, though, index investing works fine for me.