Perhaps, you are right, but your basis appears to be mainly historical paradigms and behavioral paradigms, not technological paradigms. The 800s were obviously going to be a problem b/c the 990s were basically undeveloped beasts. The MSMA had a quaint (or naive) idea that they would reduce the fuel capacity, raise the rev ceiling, and the sport would change fundamentally. Almost everyone else realized that the 800s would soon become high rev, low torque "990cc" MotoGP bikes. Peak power would not decline, and the fuel restriction would force the manufacturers to cover their bikes in electronics.
The 600s would be a different scenario. Unlike the switch to 800cc, the 600s would definitely reduce peak power output, which would change the relationship of the power to the contact patch. If the weight went down, traction control would probably become even less prevalent, though problems with cornerspeed would almost certainly be the consequence (longer races to fix?). A minor change to the gearbox rules, homologation (1 variant) for instance, the sport might actually emphasis useable power more than peak power, following the same reasoning of the 5-gear 990cc rule.
Personally, I think they should homologate a gearbox and primary ratio no matter what rules changes they use in MotoGP. Once you start going down that road; however, the sport takes on a completely new dimension. If they homologate gearboxes, primary ratio, and sprockets, they can control top speed b/c MotoGP will probably have a rev limit. So, in theory, they wouldn't have to use fuel to control performance. Furthermore, the benefit of tire performance is lessened slightly b/c a better launch out of the final corner doesn't necessarily mean a higher top speed (or acceleration) down the straight. A tire war might be easier to manage. But why stop there? If gear/sprocket homologation allows them to control top speed via a rev limit, why force the competitors to use 1 capacity and 1 rev limit. Why not let the manufacturers choose the engine capacity (maybe enforce a max) and the gear/sprocket set. The FIM could release capacity to keep the fans in the loop. The GPC can assign a rev limit for 6th gear (or any gear over the top speed limit), and use a black box to police the revs in top gear, thus top speed. If the fuel rules are still in tact, 6th gear would become a fuel economy gear, which would emphasize the importance of fuel efficiency. The gear box would essentially be reduced to 5 usable homologated gears, which would really emphasize powerband. No more need to enforce engine life rules b/c engines can be built for long life without sacrificing power. Possibly no need to homologate fuel systems b/c revs control top speed with the gearbox/sprocket homologation. If they ditch the fuel rules altogether, teams can use whatever fuel they want. They can use hybrids if they want b/c revs and top speed are controlled. The toughest part is regulating the circumferential expansion of the tires as they spin. They did it in F1 so Yasukawa knows how to make it happen.
I can think of about 4 or 5 different ways to make MotoGP interesting, fully-subscribed, cost-contained, well-sponsored, tire warred, etc. I'm not an oracle. The GPC fail on purpose. They have a mountain of cash waiting on them to claim it. They can't even take one step towards it. In fact, they step backwards away from it. I can only think of one party in the GPC who can afford to steer MotoGP clear of riches.
Detuning the 1000s is easier and cheaper, but it only works to an extent. The MSMA have been trying to detune MotoGP since the 990cc formula was introduced. If the MSMA want around 200hp (based on the old way to sanction racing), the 1000s aren't really viable b/c they'd have to make peak revs of roughly 12,500rpm.
