I would guess they don't want people complaining that there fridge went out because they plugged something else large into the same outlet and tripped the breaker... Easier to just have the dedicated circuit/outlet...
Sure the breaker will trip if you exceed the 15amps - but that won't keep the food from spoiling if you don't notice it in near future.
You may know to only plug in something with low amp draw - but someone would plug in a hair dryer or space heater if it was accessible.
Not yet retired...
Florida (Michigan transplant)
2014 Hurricane 32A
2000 Infinity (previous)