Still, people forget what an amazing technical achievement the cassette represented when it came into its own in the early 1970s. Previously, audiophiles had to fumble with cumbersome reel-to-reel recorders, threading leader tape onto 7-inch reels of 1/4-inch tape.
The early cassettes were anything but audiophile quality. The late electronics inventor Henry Kloss changed all that in 1972, when he unleashed the Advent 201 deck.
The stumbling block to quality on cassettes concerned its difficulty in capturing high frequency sounds. Unlike reel-to-reel tapes, which moved past the recording head at either 7-1/2 or 3-3/4-inches-per-second, cassettes traveled at a much pokier 1-7/8-inches per second.
That slow speed was selected to enable cassettes to run for 30- and 45-minutes per side without having to pack an excessive amount of mylar into the carrier. (Two hour cassettes existed, but used thinner tape, which was more prone to breakage.) However, the slow speed made it even harder to get good high-frequency response. Without going into arcane technical details, the problems relates to the amount of time the tape is in contact with the head, plus issues regarding bias, an inaudible electrical signal applied to the tape to enable it to record smoothly.
Kloss didn't single-handedly overcome the problem. Rather, he took advantage of incremental improvements in tape heads and electronics and put it all together, so he deserves the credit for dragging the cassette into the high-fidelity era.
I'm always amazed at people who point to the microprocessor as the pinnacle of man's technical achievement. True, computing chips are the most complicated electronic devices ever manufactured, but modern microprocessors are designed with the aid of automated tools.
People forget how difficult it was to bring radio and television out of the lab and make it practical. The cassette, in all its analog glory, is of a piece with such twentieth-century technical achievements.
P.S. Here's a fun article: 10 uses for audio cassettes. (Shouldn't it be called: "10 Things To Do With A Dead Cassette"?)