Actually, they are secular humanists, and their like can be found in all Protestant denominations. And we should all realize that they are a far greater danger to Christianity than any disagreement between Catholics/Orthodox and Protestants will ever be.
True. Liberals, as commonly understood today, are plentiful under both the Protestant and Catholic umbrellas. They are little more that the secular humanists you posit, brushed with a thin patina of Christian asides used to justify their membership in the various denominations.
My only intent was to point-out that Gamecock's Catholic "sectlets" are comprised mostly of these very secular humanists, and, discounting them as true Catholics, most of the "sectlets" are thereby removed from his assertion.