Really? What film knowledge do they actually have? What films had they made prior to their Star Wars review? I'm genuinely curious. What is their experience with filmmaking?
Experience is not needed for valid criticism. Ever. In anything. Regarding people who also have no knowledge whatsoever, even a blind squirrel finds a nut once in a while – sometimes failure is just incredibly evident from context (other films they've seen) alone.
Obviously, the most educated and best critiques will always be from people who do have the experience.
The problem, or rather one of the biggest problems, with the "where's your summer blockbuster?" argument is that it's an incredibly slippery slope. If I need to make a film – which is incredibly difficult to achieve on any level – just to be able to validly say Attack of the Clones is poorly made, what if I do, but the one I make is a romcom with no-name actors that only ever gets played at a small film festival and never goes anywhere? Besides the actual mechanic of following a film through completion, I'm not informed enough by that to go through a huge sci-fi film with a bajillion dollars of CGI and a year of postproduction and critique those elements. So now I have to go out and somehow make a huge budget sci-fi epic to critique AOTC?
No. I don't have to make any movies whatsoever. I have to see some well made ones, and perhaps read some well written stories, to inform my critique. And the critique will likely be just as valid as some big name director.
It's the same as saying only politicians can critique the political system, or only audio engineers can critique the production of the last DT album. No. That is not a valid response to someone's criticism. It's an ad hominem.