"Dino-space" is a term I hadn't heard before... Is this a newer version of the "Old-space" that people were talking about in 2005? As for re-usability on the existing designs, there were many impressive concepts for that floating around in the 80's, before they were all killed off for the Shuttle. But more recently it's not like they're just protecting what they've always had, fending off the little guy. The EELV program was rather innovative, and rather successfully reduced costs and probably improved launch reliability using some fairly unusual approaches to vehicle design. They worked out sub-optimally, because commercial demand was weaker than predicted (and never materialized for Delta IV), and Boeing wasn't exactly about to sell at a loss to boost sales. I've heard a few people argue, since the ULA merger, that ULA as a company doesn't really have the money to try to re-do the EELV's anymore, only somewhat breaking-even while SpaceX gets actual investments. Tho that might be disgruntled greybeards complaining...
Ariane 5 went expendable specifically to make it feasible to build, where Sanger and similar SSTO re-usable spaceplanes were too far-fetched to build.
Yeah, it's just a more-aggressive synonym for "oldspace". Couldn't say where it came from.
The EELV and Ariane were a reasonable approach at the time to make rockets a bit more affordable. Any way to do reusability at the time would have required a novel and exotic architecture, with a matching exotic budget. And that just wasn't in the cards.
But now it's not that impossible or expensive to ask a rocket stage to drop out of the sky and sit on its tail. (The hovering rocket is a garage project at this point, though a difficult one--but mostly because of the "rocket" part and not the "hovering" part.) Any existing stage could be modified to do the same with modern avionics, with the addition of an RCS and restartable engine (if it doesn't already have those). Sure, SpaceX's choice of 9 throttlable engines makes it easier, but you can do the "hover-slam" with just one giant one.
Any incumbent who can't manage to do so will rightly be done within a decade. And as hide-bound as they all seem to be, that might be most of them. They'll still have to deal with SpaceX's manufacturing efficiency, which might be even harder, as manufacturing inefficiency is part, for example, of Ariane's DNA. But at least they'll stay in the race.
After stage separation, it detach the entire engine block (where most of the cost is), and a helicopter captures the parachute mid-flight! (See figure 2 from the PDF)
The issue with this though is it goes most of the way back to the STS; i.e. multi-month turn around instead of days/weeks. It saves manufacturing time and materials costs (not entirely due to fatigue checking etc), but does little for integration and turn around costs.
Ariane 5 went expendable specifically to make it feasible to build, where Sanger and similar SSTO re-usable spaceplanes were too far-fetched to build.