Who are these agressive scrapers run by? It is difficult to figure out the incentives here. Why would anyone want to pull data from LWN (or any other site) at a rate which would cause a DDOS like attack? If I run a big data hungry AI lab consuming training data at 100Gb/s it's much much easier to scrape 10,000 sites at 10Mb/s than DDOS a smaller number of sites with more traffic. Of course the big labs want this data…
You are incorrectly assuming competency, thoughtful engineering and/or some modicum of care for negative externalities. The scraper may have been whipped up by AI, and shipped an hour later after a quick 15-minute test against en.wikipedia.org.
Whoever the perpetrator is, they are hiding behind "residential IP providers" so there's no reputational risks. Further, AI companies already have a reputation for engaging in distasteful practices, but popular wisdom claims that they make up for the awfulness with utility, so even if it turns out to be a big org like OpenAI or Anthropic, people will shrug their shoulders and move on.