"Incorrect"

Not really. It's debatable how much energy is lost to 'bobbing' when cycling up city hills with modern front suspension and that also depends on the fork preload settings, fork rebound settings, spring rate, tyre pressures, surface, head angles, rider technique and tyre type.

MTB's tend to run low to medium pressures on fat, high rolling resistance, tall tyres on heavy (2Kg) double-wall wheels with fat spokes, so you would need to deal with the comparatively much larger energy losses there, first, to gain anything. Suntour XCR forks alone weigh 2.2 Kg, an MTB wheel and tyre 4Kg. An issue at competition levels on low mass road bikes, maybe. But not on a 14Kg MTB, carrying a seated 70Kg rider with a 3Kg backpack and 1.5Kg of drinks.

Dive on braking is not a safety issue. It occurs on every vehicle and increases downforce on the road, and therefore increases grip. Suspension reduces tyre bounce, keeps the tyre on the road, and increases grip where this would otherwise decrease due to rebound. Grip is usually taken as the multiple of the downforce and the co-efficient of friction between the two surfaces. Bounce = less contact = less grip. Weight transfer (dive) is essential.

What fork compression does do is steepen up head angles under heavy braking. That may or may not be an issue for some. One other use of fork lockouts, for instance, is to compress the forks and lock them down, to give more nimble city handling due to a steeper head angle. Locking forks down also lowers stand-over height which can be an issue on bikes with long-travel (not the Paratrooper) forks.

There are endless front suspension designs for folders (Birdy, Moulton, Dahon, Downtube) where the benefits of having front suspension on city bikes outweigh theories about comparatively tiny energy loss when climbing, and the non-issue of brake dive on descents.

There's a user discussion here: Fork lockout doesn't get used much. It's also a pain in the ass if it doesn't get used as there's one more rusting cable to replace every year. The cable connection to the fork is also fiddly (on the Suntours) and covers get lost. I have it, but could easily live without it.

Wiki: 'The problems of pedal bob and brake jack began to be solved in the early 1990s.'

Especially on the lighter frames and oil damped forks we have now.

"Fork dive, and brake squat are not important enough, or even relevant enough, to obsess over." MTB magazine.

Yup