I was never a fan of cassettes; they were the MP3s of their time. Neither format ever sounded good to me.
Prerecorded tapes from the record companies were the lowest of the low. True, they were less expensive than LPs in the '70s and '80s, but you could make much better-sounding cassettes yourself by dubbing LPs to cassette.
Cassettes were only slightly more durable than LPs and were definitely subject to wear. Also, while the cassette you made might sound decent enough on YOUR cassette deck, there was no guarantee it would sound OK on anybody else's machine (tape head alignment had to be exactly the same on both machines or the sound would suffer).
Mix tapes were the best thing about cassettes, but they were a royal pain to make. Cueing up the LP and starting the recorder at exactly the right time took a lot of skill, but even then it was a hit-or-miss process. And if you decided you hated the third tune, you'd had to go back and redo everything from the second tune on. Recording one 90-minute cassette mix tape could take 4 or 5 hours to complete. Still, it was a great way to blow an evening.
CNET Managing Editor Jon Skillings shares my anti-cassette bias, "I loathed, hated, AND despised cassette tapes. I always found the sound quality lacking, and experienced way too many cassettes that quickly lost the ability to simply move the tape at the appropriate speed [Squeeeeeal]. And good luck finding the start of the song you wanted, at least until cassette players started getting the find-the-start-of-the-next song feature. Plus, there was just soooo much room on the cassette sticker to write the playlist of your mix tape." Tell it, brother!
I'll concede that MP3s don't suffer from any of the mechanical foibles of cassette tapes and players, and MP3s are easy to keep track of and play. Sound quality is something else again. At their best, metal tape cassettes, played on a high-end cassette machine, like a Nakamichi, could sound acceptable, probably better and certainly less digital than a MP3. But even the best cassettes were less durable than LPs; I have hundreds of over-40-year-old LPs in very good playing condition. Cassettes half that age can be useless. And cassettes lose some high-frequency detail every time you play them. LP record wear is vastly overemphasized by people who don't play records. I own lots of records I've played hundreds of times, and while they don't sound like new, they still sound great. Will you still play MP3s of music you love in 40 years?
But cassettes and iTunes/MP3s are, for the most part, "good enough" formats, and sound quality was never a big concern for the vast majority of the people who use them. The race to the bottom isn't a new problem. CDs and LPs could, on the best systems, sound great.