I find it surprising and almost funny how much ire this has drawn from people with some kind of weird "purist" attitude about the whole thing.
It doesn't seem "generally useless" to me, but it would be more appropriate to say that it's "useful only in general cases". I would say that in most circumstances, I'd want compression algorithms that balance speed and compression. I often don't zip my files to maximum compression, for example, because I don't want to sit around waiting for a long time in order to save a very small amount of space. I also don't zip without compression, because speed is not that *that* important. I look for compression that's balanced. "Compress it as much as you can without making me sit around and wait for it."
Similarly, if I were ripping CDs to MP3, and you offered me a different format that would save me 1MB per song, I'd jump on board. If you told me that it would save me that space by requiring 1 hour to compress, and then another hour to decompress before I could play it, I'd tell you to fuck off. If you told me it would drain my battery life on my phone to play it, I'd say it's not worth the trouble.
So I don't know if this is the right metric or the most useful metric, but certainly there could be a metric for compression that deals with "total space savings" vs. "time and complexity in compressing and decompressing". Such a metric could actually be a solid indicator of which compression is useful in a vague general sense.