[bct]

The conflation of "semantic HTML" with "the semantic web" has done immeasurable harm to both causes.

Yes, debating whether to mark up your forms using UL or OL or LABEL or SPAN or DIV or DL or TABLE or ... is a total waste of time. That doesn't tell us anything about the usefulness of machine-readable linked data, though. The two subjects have nothing in common except a relatively unusual adjective.

[bct]

Or, to put it another way, there are two different kinds of semantics in play; the semantics of a document (this is a title, this is a paragraph, ...), and the semantics of the subject of a document (this is the price of the item, this is how many we have left in stock, ...).

The costs and benefits of enhancing one are different and separate from the costs and benefits of enhancing the other.