This is getting ridiculous. Race results show that it depends on terrain. Which is why every racer that can switches back and forth from HT to FS depending on terrain. By the way, that is what every person with a functioning brain has been saying all along: it depends on terrain.

To claim that it is all a marketing ploy borders on idiocy, given the prices of high-end racing hardtails -that are cheaper to design and produce than a full suspension bike.

If a Thudbuster makes you happy all the power to you. But a Thudbuster will not help with traction on a corner at 20mph and it also won't keep your rear wheel from bouncing on a rocky climb. It is also really poor advice for the OP. Same with saying that full suspension only helps on downhill and hardtails climb faster. It is simply not true and really poor advice.