Dan Luu argues that he notices severe bugs in products that teams insist work fine, and traces this gap to how fans of something—whether employees, users, or enthusiasts—develop psychological blind spots to its flaws. He uses search engines, Blackboard, and forum software as examples of products widely disliked by actual users but defended by insiders.

• Products can be severely broken (requiring workarounds, producing spam-filled results, cheating on performance metrics) while internal teams genuinely believe they work well, then fail publicly when real users encounter the same issues Luu spotted.
• People exhibit strong motivated blindness toward things they're invested in: Volvo forum users deny reliability data, Blackboard employees were shocked it was widely hated, and Discourse developers implemented performance cheating while apparently believing their software was fast.
• Luu suspects this blindness is partly about mental barriers people construct—acknowledging a flaw in your work or something you love requires confronting cognitive dissonance, so teams rationalize away contradicting evidence.