Einsteinians reject, more or less explicitly, the absurd consequence, Einstein's spacetime, but continue to worship the underlying premise, Einstein's 1905 false constant-speed-of-light postulate:
What scientific idea is ready for retirement? Steve Giddings: "Spacetime. Physics has always been regarded as playing out on an underlying stage of space and time. Special relativity joined these into spacetime... (...) The apparent need to retire classical spacetime as a fundamental concept is profound..."
Nima Arkani-Hamed (06:11): "Almost all of us believe that space-time doesn't really exist, space-time is doomed and has to be replaced by some more primitive building blocks."
Frank Wilczek: "Einstein's special theory of relativity calls for radical renovation of common-sense ideas about time. Different observers, moving at constant velocity relative to one another, require different notions of time, since their clocks run differently. Yet each such observer can use his "time" to describe what he sees, and every description will give valid results, using the same laws of physics. In short: According to special relativity, there are many quite different but equally valid ways of assigning times to events. Einstein himself understood the importance of breaking free from the idea that there is an objective, universal "now." Yet, paradoxically, today's standard formulation of quantum mechanics makes heavy use of that discredited "now."
"Fotini Markopoulou-Kalamara, a theoretical physicist at the Perimeter Institute, said, "I have the distressing experience of physicists telling me that time is not real. ... It confuses me, because time seems to be real. Things happen. When I clap my hands, it happened. ... I would prefer to say that general relativity is not the final theory than to say that time does not exist." Time is a prime conflict between relativity and quantum mechanics, measured and malleable in relativity while assumed as background (and not an observable) in quantum mechanics."
"Rethinking Einstein: The end of space-time (...) The stumbling block lies with their conflicting views of space and time. As seen by quantum theory, space and time are a static backdrop against which particles move. In Einstein's theories, by contrast, not only are space and time inextricably linked, but the resulting space-time is moulded by the bodies within it. (...) Something has to give in this tussle between general relativity and quantum mechanics, and the smart money says that it's relativity that will be the loser."
"...says John Norton, a philosopher based at the University of Pittsburgh, Pennsylvania. Norton is hesitant to express it, but his instinct - and the consensus in physics - seems to be that space and time exist on their own. The trouble with this idea, though, is that it doesn't sit well with relativity, which describes space-time as a malleable fabric whose geometry can be changed by the gravity of stars, planets and matter."
"And by making the clock's tick relative - what happens simultaneously for one observer might seem sequential to another - Einstein's theory of special relativity not only destroyed any notion of absolute time but made time equivalent to a dimension in space: the future is already out there waiting for us; we just can't see it until we get there. This view is a logical and metaphysical dead end, says Smolin."
"Was Einstein wrong? At least in his understanding of time, Smolin argues, the great theorist of relativity was dead wrong. What is worse, by firmly enshrining his error in scientific orthodoxy, Einstein trapped his successors in insoluble dilemmas..."
"Einstein introduced a new notion of time, more radical than even he at first realized. In fact, the view of time that Einstein adopted was first articulated by his onetime math teacher in a famous lecture delivered one century ago. That lecture, by the German mathematician Hermann Minkowski, established a new arena for the presentation of physics, a new vision of the nature of reality redefining the mathematics of existence. The lecture was titled Space and Time, and it introduced to the world the marriage of the two, now known as spacetime. It was a good marriage, but lately physicists passion for spacetime has begun to diminish. And some are starting to whisper about possible grounds for divorce. (...) Einstein's famous insistence that the velocity of light is a cosmic speed limit made sense, Minkowski saw, only if space and time were intertwined. (...) Physicists of the 21st century therefore face the task of finding the true reality obscured by the spacetime mirage. (...) Andreas Albrecht, a cosmologist at the University of California, Davis, has thought deeply about choosing clocks, leading him to some troubling realizations. (...) "It seems to me like it's a time in the development of physics," says Albrecht, "where it's time to look at how we think about space and time very differently."