... because Japan.
Come to Japan where depending on where you live in the country you'll be supplied with power of a different frequency, Eastern Japan has one frequency and Western Japan has another, both are nominally 110 volts, plugs are the same for both areas. Whilst 90% of equipment doesn't really care and will work regardless the other 10% will have all kinds of issues from intermittent faults to releasing the magic smoke.
And sods law requires that the one item you really need to work is the one that'll crap it's guts out.