haha.. maybe he realized that some pool light, or other rubber gasket fits a lens and now renamed it to DD and sell it for 25(?)

)
I think the problem is in the sensational tone of the ad.
"Now Photographers everywhere can take full advantage of Canon's non Weather Resistant lenses and even the more affordable third party lenses while still benefiting from the increased durability of a Dust and Moisture resistant Camera/Lens combination!"
"just use your lens as usual but with the added peace of mind that both of your investments are protected against Dust and Moisture."
It won't make a non weather sealed lens invincible and people will risk damaging their cams and lenses.
I wonder what kind of warranty it comes with. Claiming that it provides the same protection as sealed L lens and making a non weather sealed lens a sealed one comes with responsibility...