Is a longer onboarding tour a sign of a complex product, or a weak design?

We kept adding tooltips, pop-ups, and step-by-step walkthroughs to teach users how to use our platform. Yet, drop-off rates during signup kept creeping up. When we finally stripped away the tour and redesigned the interface to be self-explanatory, activation rates jumped. It taught us that if a product needs a manual to explain itself, the design itself needs fixing.
How do you balance teaching users your product versus making it naturally intuitive?