That's like saying the main difference between a 57 Chevy and a 2112 Ferrari is the use of carbon fiber in the body panels.
I love this quote and may be forced to steal it!
I love the sound of vinyl, at least on some albums. There. I've said it. I still dig out my half-speed mastered version of "Dark Side of the Moon" and listen to it by the light of my lava lamp.
However, I'm not going to kid myself that it's because analogue is "more accurate" or "has more high end details" or "moves more low end air". A good digital recording is more accurate than a good analogue recording. The difference is that "accurate" isn't a synonym for "pleasing to the ear". The things that make analogue sound better to some of us are FAULTS with the recording accuracy, not a demonstration of how good they are. It's a whole mix of things: analogue distortion, lack of resolution at higher frequencies, slight errors in the pre-emphasis/de-emphasis filters (for tape), errors in the RIAA curve (for vinyl), limitations in the mastering process, etc. etc. If it sounds pleasing, none of that matters--but we're on a hiding to nothing if we try to argue that analogue is better or more accurate.
A few other points:
First, I notice the OP wasn't talking about a master tape. He was talking about a cassette. Now, if he likes the cassette sound that's great for him but cassettes were pretty appallingly bad quality really. Depending on the type of tape (a commercial recording would likely be on a pretty basic oxide) the top end will sound smoother simply because it isn't there--they rolled off at about 15 or 16k. Heck, maybe they do move more air because the amp isn't "wasting" any energy trying to reproduce HF!
Second, something that nobody has mentioned is comparing live sound to the recording rather than comparing analogue vs. digital recordings. This is a far better test of accuracy--and, having done it, I can guarantee that the digital will win hands down. Played back on decent speakers in the same studio where the recording was made, the raw digital recording makes a passable imitation of the live performance. Analogue (done on a good reel to reel at a high tape speed) makes a valiant effort but doesn't do as well. And a cassette is more like listening to a 128k MP3 than reality.
Now, none of this changes the fact that analogue can be nicer to listen to. However, as soon as you move from "I like the sound of analogue" to "Analogue is more accurate" you also move from a valid opinion to pseudo technical babble.