If I go and pick up something that doesn't sit around at room temperature well (let's say a milkshake), and drive 20 minutes home before eating it, I'm not going to ding the restaurant for the fact it's melted.
If, however, milkshakes are offered for takeout (reasonable), but then a third delivery party gets involved and starts offering them for delivery, anyone ordering it will have the impression of "I ordered a milkshake. It arrived to my hand melted! 1-star, bad!" Since they clearly aren't thinking enough to -not order the milkshake in the first place-.
Milkshake is an extreme example to demonstrate the point, but applies to anything that doesn't sit well (previously mentioned burger included), with the added trouble that customers are less likely to know what will sit well.