I see a lot of fan art that depict this move (even though nothing of the sort happens from the show/series where the characters came from) and even in Nichijou we have the school principal giving a deer a tiger suplex:
Shuichi drops a suplex in Gravitation
Episode 87 of Gintama is: "Perform a German Suplex On a Woman Who Asks If She or the Job Is More Important"
From Lagrange, the mechas do one:
And all the endless fanart:
Why is this so popular? Is this because wrestling is popular in Japan? But why this specific move?