They're also anonymous, so you should assume the worst. This is especially true when the supporting evidence is suspect (ie. a bunch of arbitrary picked numbers). On the other hand the BLS's methodology is documented (https://www.bls.gov/opub/hom/cpi/), so I'm willing to give them a pass even though their incentives might be skewed.
>(what would it be?)
their beliefs? "agenda" here doesn't have to be something nefarious. an anti-vaxxer's agenda is anti-vaccine, but that doesn't mean they're scheming to get everyone infected.