This article, and possibly the owners of the site, seem to muddle together several problems:

1. bot traffic causing infrastructure cost

2. scraping circumventing paying for licenses

3. the risk of hacking

You missed the speculated motivation: unrestricted prediction markets, which are an open and broad incentive to do whatever actions might provide a slight edge in betting.

Webscraping is among the more benign things that gambling-on-anything can drive. And even that has a negative impact, as seen here.

I have no idea why those sites are legal.