Those who are building or rebuilding their credit often have little choice other than to accept cards with AF.
Once they have moved beyond those starter cards, however, an AF can still be worth paying if the rewards make it worth it.
For example, Chase Freedom has no AF, but the 3% rewards tier is limited to the top three monthly spending categories and $600 in spending per month. Chase Freedom Plus has an AF of $30 but the 3% rewards tier applies to the top six categories and is not capped. For those who routinely hit the Chase Freedom $600 spending cap, it will usually be worth paying $30 a year for the benefit of having no rewards caps.
The AF cards I currently have and will gladly pay an AF for are:
Amex Gold Delta SkyMiles (AF $95, waived the first year). Reason: This card pays for itself many, many times over.
Citi Platinum Amex (AF $125, waived the first year). Reason: Lounge access and annual complimentary domestic companion ticket.