To alleviate the need for extension cords which are a big cause of fires.
That said, 18" is absurd.
And outlet multipliers, which are good at putting more load than planned on the circuit.
Do they even let you put the old-style non-fused/breakered outlets in anymore?
All countertop (small appliance) outlets are required to have GFCI protection and most places necessitate two separate 20A circuits for the space.
US outlets don't have any sort of fuse/breaker built in.
Some are GCFI which can detect abnormal current.
GFCI, AFCI, and overcurrent protection are all orthogonal protections. US receptacles do not have overcurrent protection built in.
I'm pro-autonomy and the NEC has recently jumped the shark (eg AFCI and "tamper resistant" receptacles), but most of its requirements are quite reasonable and written in blood.