That’s because the sequel had to differentiate itself from the first one. It had to tell you not only that it was a similar idea to the first, but also that it used discs instead of tapes.
The first Walkman had nothing to differentiate from. It was the first.
Discman is Sonys CD Walkman line.
My point was that Walkman never mentions tapes, so why mention the media format in the sequels name.
That’s because the sequel had to differentiate itself from the first one. It had to tell you not only that it was a similar idea to the first, but also that it used discs instead of tapes.
The first Walkman had nothing to differentiate from. It was the first.