It has to be able to take off and land on a carrier to work its way into USMC Aviation. And they are going towards a F-35-pure fixed-wing force anyway. So, no. Not saying I agree with the F-35-pure MAWs, but there it is.
Why did the USAF stop using the A-1? The same reasons the USN did, one imagines.
By the time they stopped, the youngest airframes were nearing the twenty-year mark. There were other planes that could do the job of delivering ordnance to the ground. Those planes could get to the operational area faster and work synergistically with the rest of the strike package and the constraints of the friendly airfield (be they traditional ones or carriers on-station somewhere). And the USAF in particular already had a newer model of the A-1 coming on-line within a few years. It was called the A-10.
You know, for that CAS mission the zoomies don't want and never do.
It is interesting that the USAF gets so much grief for not wanting to do CAS, and that the A-10 is the absolute bestest airframe to do it in living memory, but no one says anything to the USN or USMC who do CAS all the time (the latter, inarguably, being known for it) and have never flown A-10s so far as I know (I mean even an active-duty test pilot here, not in an operational squadron).
For those interested, the article that DOC is likely referring to (almost verbatim) can be found
here. From what I can tell, its central theme is based on this
memorandum that, while interesting, is mostly redacted, with the notable exception of a chart detailing mission/task training hours, where the CAS line is blank (but SEAD, for example, is not).
Statements to the contrary notwithstanding, it is possible that the USAF envisions its F-35s doing other things than CAS for the time being while jets like the F-16 and F-15E do the CAS role. Given its fundamental attributes, the F-35 seems tailor-made for SEAD and precision strikes, so I get why the USAF would focus on those missions for the time being.
Since we are talking about, if you want to know about US military CAS doctrine, look
here. And try
this paper for a good overview of the A-10's contribution to CAS over the last forty years, the challenges it faces today, and what it all means for the poor saps getting all hot and bothered on the ground.