The lower ("less-interesting-of-a-daily-read-to-me") quality blogs have in the main only gotten worse over time as the programs became less valuable for consumers.
The massive devaluation hits customers have faced from the airline mileage programs in the US aren't due to the credit-card issuers and the blogs covering the credit-card issuers in the space. Those devaluations are caused by the US3 airline cartel kingpins and rooted in the USG-granted allowances given to the US3 airlines; and they've unleashed an infection that is undermining the value that consumers get from non-US airline mileage programs too.
Blaming bloggers and credit card issuers for the massive program devaluations is akin to putting the cart before the horse and punishing the cart for horse being a bad horse.