After the Second World War in Italy the carmakers realised that it would be a long time before everyone who needed a car would be able to afford one. So the smart Italians switched to designing and producing motor scooters: these light, affordable, ergonomic Vespas, a low cost product available to everybody.
Needless to say, Vespa was the brand of the time (and arguably still is) and it grew more and more popular across Europe, until, in early 1950s, it reached the USSR. All of a sudden this youthful and cheery means of transportation coincided with the Khrushchev Thaw and it was decided to launch the Soviet line of motor scooters. Machinery wise, it was viable: since the war times, a few factories had been idle, so it was only a matter of design.
The design couldn’t have been an easier problem to fix: Europe was going through a real scooter boom and, since the copyright laws were not as aggressive as they are nowadays, it was decided to simply copy some. The choice was there but, after much consideration, Vespa was chosen as the prototype.