That would be believable if people didn't substitute 1 of 5, or even 4 quarts of their oil with a full quart of LOS. I was at one time young (stupid) enough to do so, driving around with oil that was as thick as cold oil in a fully warmed up engine. The Jeep keeps on ticking, the Infinity J30 I did that to was also a happy little car until sold. I heard of people doing the same, as well as bumping up a grade, and they have driven the cars without engine failure.
I can see sulfur eating away the colored metals after God knows how many miles in an engine where someone would choose the lazy route to thicken the engine oil with gear lube, instead of replacing a gasket. Again, the amount of time is not known to me, and many people dump their cars at an early age, and he reasons for a failed engine could be mislabeled due to unknown history.
Same can be said for people using MMO, ATF, or diesel in the crank case.
That page may as well say "Bad things may happen if certain decisions were to be made, maybe."