Why is passer rating still being used as a stat?

Passer rating is a fundamentally flawed statistic that sets arbitrary standards and gives equal weight to unequal categories. It should be given credit, when first conceived, as an attempt to express an overall rating of a team's passing game that went beyond total yards, which was a watershed idea at the time in formulating new and better statistical models that gave us more effective measurements than just the traditional basic numbers. But our understanding of football statistics since then have long since left this initial primitive and clumsy model behind and given rise to far more useful formulas such as AYPA. Why is passer rating still being cited?