I don't think you can deem someone healthy on the basis of their looks which can be deceiving (as commented on Bear etc..), the converse I think isn't as absurd -especially in person (but also from photographs) to bring criticism to their ideas. Although also as pointed out sometimes this can be a transition/healing period where people can not look so well, but with long term proponents and "experts" I don't think this is the issue
When people make claims about their diet using the words "ultimate" "diet meant for humans" "healing/detoxing" "most efficient use of fuel" "regenerative" it is perfectly natural for someone to expect that this will manifest physically in a positive way, not necessarily compared to various ideals of beauty but have a visible vitality.
also worth mentioning most people that eat conventional 'healthy' diets that happen to look well usually don't make these claims, and will tend to talk more about "moderation" "exercises" etc...
I can say from working in photo industry that while its very true that just about anything can be done with still photography and that virtually all print and web based media is retouched, it still remains that video can only distort via makeup and lighting. Minus the unlikely budget of Graham or Aajonus for CGI. Granted that webcams will not be the most flattering, but especially something shot outside in the sun is open game for commentary IMO.
If I'm not mistaken, another excuse (or sidenote) often responding to Grahams appearance is his claimed high level of fitness, and success (they claim) of increased fitness with aging athletes. It's fairly ironic that few of his disciples actually can create any muscle definition at all in comparison to his build, which is actually quite tiny in person. Another give away (which on top of pictures as I've said I do think can be a window into their program/success) Is that through his message boards etc.for a time he was just a completely irate intolerable son of a bitch. This seems to have improved (probably pointed out by an underling) and he tends to pull it together during interviews via my next point which is he's known to chomp down on bagles and such. Caught also by an intern at his fasting camps with Subway wrappers in his car. That said I think he does for the most part follow his low fat raw vegan regime, and the fact that being the most successful long term example of his ideas his actual results should have more of an impact on people than they do.
As for Aajonous I've never seen him personally, discounting pics I think he looked like a badass in the Ripley's episode on "high meat" which clearly tried to paint him as a creep. More recently on "The Doctors" I thought he was looking not so well (although for someone in his 60's definitely healthy enough) but perhaps due to the antiseptic and ignorant panel and audience he seemed a bit jittered in presence as well.