Because it invites people to game the system. There are plenty of free lists and they overlap significantly. I'm pretty sure their intersection is also very similar to the core of the HN list.

> Because it invites people to game the system.

Please elaborate, how would they game the list?

They can already see if a submission is throttled/flagged/etc.

You can do A/B tests to figure out what sorts of behaviors ride the line of triggering bans vs what kinds of behaviors result in an outright ban. It lets you optimize for just-trash-enough to not get banned, which is not a desirable end state for users.

That's a decent point, but I'm not sure if it's outweighed by the ability for users to discuss and validate the disallowed sources.

Probably so the offending sites don't realize they're being blocked.

pretty easy to see when they don't get traction / get flagged automatically.

the only thing it really does is prevent others from seeing what's being censored.

> pretty easy to see when they don't get traction / get flagged automatically.

or they may think the content itself is the problem and spend resources trying to tweak it.

I think an analogous situation would be saying if the username/email is valid when there is a failed logged in attempt. Its a very minor thing but why give someone who is trying to abuse the system any help?

>or they may think the content itself is the problem and spend resources trying to tweak it.

A spam site knows it's a spam site. It's already tweaking domains and thats why the list is so big. It's relatively easy to buy new domains.

For the remaining 5-10% of legitimate sites I imagine HN isn't enough of a draw to care about tweaking content. They will save that level of curation for the Twitters, Facebooks, and maybe reddits in some cases.

>I think an analogous situation would be saying if the username/email is valid when there is a failed logged in attempt. Its a very minor thing but why give someone who is trying to abuse the system any help?

It does bring up the honest question of "how much do you inconvinence honest users in order to punish dishonest users"? And honestly it's a bit tiring to keep being assumed that I'm a dishonest user. If you trust me so little as to give an IQ test just to let me post a link (reducto ad absurdum), why would I bother as an honest user? Meanwhile the dishonest users will simply work around that or hire some cheap labor.

I think they just don't check. They just post to as many sites as they can. It's high volume, low reward. HN also has a small readership with a limited interest, so it's not likely to be a spammer's top priority.

Cause spammers would buy a new domain and do the same thing again, as opposed to plausible denyability.

they can do that without the list. as soon as you see your post doesn't get traction, make a new domain, or have multiple in the first place.

The vast majority of all posts get ~0 traction. Even prolific posters of highly-upvoted links like todsacerdoti* are probably only getting around 1 in 10 to the frontpage at all, let alone for a meaningful period of time.

* https://news.ycombinator.com/submitted?id=todsacerdoti

Have you ever checked /new? Not getting any traction is the default, not an exception. Plenty of submissions end up with no upvotes and very few clicks, hence plausible denyability.