This is a confusing statement to me. The actual job description for these paid staff is to provide services to guests. That's literally the entire reason for their employment. It's not that silly for someone to wonder why Disney would charge extra for their service staff to perform a service for you. You can argue as to which services they were hired to do, but I would argue that what has always put Disney a notch above the rest is the lengths they used to go to serve their guests. If they choose to offer less complimentary services than the Motel 6 up the road, that's pretty telling.
Disney likely wouldn't be in this grocery delivery pickle if they didn't charge exorbitant prices for their own groceries. And people wouldn't be forced to cook and pack their own meals if Disney Restaurants weren't also so expensive.
Instead of keeping prices reasonable so people don't look elsewhere for food, they choose to price gouge instead? By all accounts, it sounds like it's nearly impossible to get your groceries delivered without them coming through the front desk - since lobby pick-up is a no-no and the delivery entrance is the only place Amazon and grocery delivery companies are allowed to go. If my family ordered our groceries for the week onsite, we'd have at least 10 bags or boxes of food - 60 bucks? No thanks. I'll simply spend one less morning spending $$$ at a Disney park and drive myself to the store to pick up my own groceries. Disney's loss.
To be honest, this just solidifies our family's decision to continue staying at offsite resorts - where the staff go above and beyond, I get groceries delivered to my door for free, parking is free, and I get a 5 bedroom pool home for 1/10th the cost of staying at a grand villa onsite.