I see [ubiquitous computing] as analogous to "Physics" or "Psychology," terms that describe a focus for investigation, rather than an agenda.
Why don't others see it the same? I think it's because the term is fundamentally different because it has an implied infinity in it. Specifically, the word "ubiquitous" implies an end state, something to strive for, something that's the implicit goal of the whole project. That's of course not how most people in the industry look at it, but that's how outsiders see it. As a side effect, the infinity in the term means that it simultaneously describes a state that practitioners cannot possibly attain ("ubiquitous" is like "omniscient"--it's an absolute that is impossible to achieve) and an utopia that others can easily dismiss. It's the worst of both worlds
Mike also identifies Artificial Intelligence and Ambient Intelligence as having this problem too. In they eyes of your detractors you'll never get there, you're crazy for thinking it's worth trying, and the steps along the way don't measure up to the vision. I'd add that Virtual Reality also has this issue, since the reality part is unattainable (and if the uncanny valley is to be believed, steps towards it can actually make things worse).
I like the solution Mike offers to this. Rather than inventing new terms, he's simply asserting that ubicomp has already happened, and has been with us since around 2005. There's more on this in his talk from UX Week last August which was great, and no doubt also in his upcoming book.
I like the idea of framing these unattainable words as being about now, not some distant future, and working with that to see where we go next. It's fun to imagine a light misting of comp, that will steadily increase in saturation until it's ubi... a luminous bath, some might say. A version of Gibson's "the future is already here, it's just not very evenly distributed", perhaps.
I'm also wondering if there's something to these limitless phrases that attracts academics. I have degrees in artificial intelligence and in virtual reality so you might think I'd know, but I always felt late to the party in those circles, like I'd missed the initial buzz and arrived in time for the hard defensive slog. And hey, Web 2.0 feels like that sometimes too - arguably, whatever's next is already here and we should take a leaf out of Mike's book and start declaring it so. When Web 2.0 was first coined, it wasn't about the future!