There is some truth to this, and the article touches on it in passing (of course, it's The Guardian, how could they miss the opportunity?)

But there's more to it than that. Certainly manners were circumscribed as a way of denoting hierarchy, and as a result those not on the top mocked the rules of their "betters", claiming that the rules existed only to exclude others.

However often the rules themselves had purpose, and in specific, hygienic ones. The use of cutlery, not sharing cutlery, separating food from the table with a plate etc were practices that reduced disease transmission. In this regard, democratization of manners would be better if some manners of the "uppers" were spread widely as opposed to being discarded. Of course other rules were designed to exclude others, and those ones should be (and many have been) chucked out. But it's worth being selective.