Indeed Mickey! When I read your post in preview (your first two lines) my first thoughts were how the house of mouse dealt with the dearth of options surrounding them in Anaheim (prior to them paving paradise and putting up parking lots) - it was indeed one of Walt's greatest disappointments about the Anaheim park was the cheap junk that sprang up all around the park, capitalising on the captive market.
Disney simply did unique and better products, things you couldn't get down the road (cough burgers cough) - things that took you out of the everyday - and as has been mentioned - turkey legs, mickey waffles, mickey ice cream bars. Sure, much of it is just a different shape, but people still buy it - and today more than ever with everyone pausing to instagram their food before they eat it - a unique food item would sell like... waffles!
Even just something as simple as a turkey leg - although i daresay the Australian market doesn't have quite the same taste for turkey that the Americans do... but there has to be something that they can do which is unique, capitalises off their licensing or brands, that would see people willing to fork out for it, even if it is exhorbitantly overpriced?
It's not enough to serve standard fare (like popcorn, or hotdogs) in a container printed with a licensed character and assume that that is enough to justify an obnoxious price tag.
I'll put my money where my mouth is on ideas*:
A waffle in the shape of the WB shield
An ice cream bar (think Magnum) in the shape of the Batman crest
take the ice cream bar a step further, and make it a 'home made' affair. One of my best memories at Knotts was an eskimo pie, nothing particularly interesting about it - except it was hand dipped in molten chocolate and had choice of nuts \ sprinkles etc
Do dagwood dogs, but have the Joker's graffiti smiley stamped on them
Do a burger with a coloured bun - green for green lantern, black for batman, red for superman. each burger should be different, similar to the gotham range currently on offer
Hand make fairy floss - but get a guy in who makes ART out of them (i'm sure we've all seen the YT videos of guys doing this) instead of the pre-packed months-old variety
A signature iced confection (think Dole Whip) - perhaps theme it to Taz Devil (and have Taz's image be part of the blender that makes it - the motion and sound of a blender suits Taz perfectly)
Thats another tangent - don't just make the food unique - make the method of service unique too! In addition to the Taz blender contraption, what about a Rube Goldberg style contraption (one could theme to Willy Wonka or similar) that prepares \ serves the food when the order is placed (and then somehow automatically resets) - it doesn't even have to 'actually' serve the food so long as it LOOKS like it does... I CBF googling it but i know i've seen a video of a restaurant (i think in a theme park) that actually delivers your food on a roller coaster like delivery contraption - and i'm sure someone will point it out to me in due course...
We usually criticise gimmicks here, but in this case, i think the parks need a gimmick to make their food have a point of difference.
Don't get me wrong, the quality we have lamented here for almost 3 pages does need to improve, but its not enough to make your burger as good as the one across the road, or even better justifying the more expensive price tag, if the experience is much the same (i'm talking bored or frazzled staff (depending on the time of day) who are either not interested in serving you or too busy to get your order right) - I think this is why Dreamworld's Parkway has largely fallen flat too - they tried to be an alternative to a road house, by delivering much the same as a road house, in a less convenient spot.
Improve the food - do whatever you have to with the prices, but make it an experience worthy of staying in park and paying a premium. I'm not talking bloody projection mapping (that might swing in Disney's premiere dine-in restaurants but it won't wash in Movie World) - i'm just talking about making your food unique enough that people won't mind paying extra to buy it.
*Some ideas are quite feasible and realistic, others are a stretch just to try and tie the brand. Others might not have the desired effect (i know that the black burger buns have had mixed reactions in outlets like Burger King), but the point is i'm just a guy who doesn't work in Village coming up with ideas and tie-ins. Imagine what they could come up with with the knowledge, licensing etc - i'm sure products of similar nature have been done in other parks, probably many using the Justice League characters to full advantage - these are just ideas, and i recognise not all of them would be commercially viable - so there isn't a need to hyper analyse every suggestion - it was just to get some creative juice flowing - by all means come up with some better ones of your own...