Well, believe it or not, I still have a lot of music in cassettes, about 1000 hours. I used to have a very high quality Aiwa deck with 3 heads and bias control, bought in 1989. After that gave up recently (probably could have gotten it repaired, because the heads were alright, but could not get any body to repair it in Kolkata), I got one from Onkyo (a small form factor single cassette deck, decent one, but no match to the Aiwa which was about five times costiler). Let me just say, I have cassettes from as early as 1981, and they are still in top condition. I have always used high quality cassettes from TDK, Maxell, Denon and Sony. Bulk of my cassettes have chrome bias and recorded with dolby B. Some are metal and some are normal. I still do have a few blank metal cassettes (still original packing) left with me. Last year when somebody was looking for blank metal cassettes in this forum, I thought long and hard, but still could not part with them, because I still intend to use them.
To give you a a particular example:
There is a live recording of Ali Akbar Khan (Sarod), L. Subramaniam (Violin), Zakir Hussain (Tabla) and Ramnad Raghavan (Mridangam) playing together two ragas: Raga Nattai (or rag Jog as known in Hindustani nomenclature) and Raga Sindhi Bhairavi. I have this recording in cassette, got it some time in later half of the eighties in the US. Recently I bought the CD of the Raga Nattai (same performance) now available in India in CD. To tell you the truth, the quality of the cassette is FAR FAR better than the CD even in my Onkyo (which albeit a decent one does not take care of the biasing in the most appropriate fashion I think, because a cassette recorded with dolby C for example loses too much of db and hence dynamic range in dolby C, which a better deck would do proper justice to).
However, I agree there are only a handful of people, still using cassettes as one of the main sources, I suppose.