But dark energy was an observational result, not some theoretical flyer.
The equations are well understood: the Einstein field equations from General Relativity. The observations are simple: how do the galaxies move, and how does that change with distance. Careful observations showed that those didn't line up. That leaves three possibilities: either the observations are wrong, the equations are wrong, or something else is out there.
The observations weren't wrong. They were reproduced by other groups. They were tested by different types of observational measurements. The effect is real.
Are the equations wrong? Perhaps, but, other than this one ugly fact, there was no theoretical basis for rewriting the theory. Nobody had any new approach that would fit all of the old data, and account for the cosmological observations.
There was an out, however. Preciently, Einstein included a free parameter in his equations: the Cosmological Constant. It was always assumed to be zero, and Einstein died thinking that it was a mistake to include it. However, the observational anomaly simply goes away if this is set to a certain non-zero value. This is what has been given the name "dark energy".
Dark energy is an independently testable hypothesis. It has already survived a number of observational tests, and others are planned. There are several models describing the nature of dark energy, and these are testable, too. Experiments are under construction or taking data as we speak.
It seems you object to some part of this approach. How should it have been handled differently?
It's a speculative field, and shouldn't be represented as anything else.
It's fundamentally an observational field.
Yeah, but space scientists are still Drama Queens.
It's interesting to see a thread with only two real participants and a lot of hangers on.
Well, the problem is there could still be another resolution of the problem, based on something else we haven't thought of yet. Dark energy is still ad hoc ; it's not directly observed, but rather hypothesized to make the equations fit. The GR equations reconcile a lot of observations, and so shouldn't be cavalierly discarded; but at the same time, 'dark energy' doesn't have the same level of certainty, as, say, neutrons.
I think the neutrino analogy is valid. Fermi came up with neutrinos because conservation laws were apparently being violated, and nobody wanted to throw out conservation laws simply because of anomalies in one phenomenon. However, IMO, neutrinos were still a rather dodgy ad hoc hypothesis until they (or their effects) were observed directly.
We should have a special category of 'stuff', that exists because we need it to exist to keep a valuable theory from falling apart, but where there's no other independent verification of its existence. And we should be careful not to talk about such 'stuff' in the same way we talk about more substantial stuff.
Having said that, I don't attend cosmology conferences, and I'm sure you're right that the guys in the field are probably appropiately careful about how they talk about such ideas; maybe the advice needs to be given to science journalists and not to cosmologists.
Presciently. (A typo, not a misspelling.)