Sinkhole in a sentence as a noun

Does the author really want to stake his reputation on the fact that cryptocurrencies are nothing more than 'an intellectual sinkhole?

NAT is not a security feature, is not good for the internet, and the sunk costs spent building an ALG for every protocol to work around it is a significant development sinkhole.

[Edit: There are now quite a few HN posters in multiple discussions about this action who are saying their innocent use of No-IP is being undermined because Microsoft's sinkhole is getting in the way.]

The most famous of these is in Pennsylvania, where a town had to be abandoned because the coal mine underneath it was burning and releasing noxious gasses up to the surface, along with the occasional flaming sinkhole.

On June 26, the court granted our request and made Microsoft the DNS authority for the company’s 23 free No-IP domains, allowing us to identify and route all known bad traffic to the Microsoft sinkhole and classify the identified threats.

If an innocent citizen can report events and locations, why wouldn't the cartel use it to fool authorities?Third, it looks like an offer to throw even more money into the 'war on *****' sinkhole, only disguised as 'fighting with technology', 'technological workaround to the fear', and other BS propaganda.

Consider these phrases:"everything wrong with Silicon Valley""crypto-libertarian political agenda that smacks of nerds-do-it-better paternalism""intellectual sinkhole""near-total obliviousness to reality""alarmingly magical thinking""unchecked predatory capitalism""short-sighted hypercapitalism"There are interesting conversations to have around bitcoins but I can't quite put my finger on why they tend to get so intense.

Sinkhole definitions

noun

a depression in the ground communicating with a subterranean passage (especially in limestone) and formed by solution or by collapse of a cavern roof

See also: sink