I'll ask the dumb question....
The cabins have a full kitchen (fridge, microwave, oven, coffee). And a nice sitting area (if the table and chairs ever come up in auction, I will get a set).
Most of us campers in campsites have our stoves/burners/ovens with us. Or folks use the cabin amenities (which include these things). Several online vendors can deliver groceries. Thus you have the MEANS and you have the WAYS.
Not sure what the issue is here for the OP.
I'm all for free enterprise and capitalism. Maybe P&J won't, on their customer analysis, have enough folks come in too early to buy a sausage and biscuit plus OJ. There may be a FEW people like the OP (who discards having a fridge and stove/oven/micro/coffee) and want to pay a premium for a grab-and-go breakfast. That does not a business-case-make.
If I am one of the few customers who can't float the business case, I am okay with that. I run that same equation through my head every meal (cost/availbility/means of a meal versus the convenience/speed/expense) in the parks. It's an all-the-time consideration.
TL;DR: I'd like to hear why the OP can't manage breakfast at their cabin/site. I don't eat in my room either: I have breakfast at my site. My breakfast nook is my campsite which is a wonderful breakfast in the big outdoors.
Bama Ed