I agree 100%, but it is a fact of life, and sometimes it's better to just minimize the fuzz and focus on the things that matter.
Your argument is perfectly valid and applies to offline activities as well (what stops a competitor from walking through the aisles of a Walmart or Costco?), but this is a battle that can't be won, there are too many parasitic actors. It is human nature.
Understanding your competitor's pricing is not "parasitic", it's research. Every company I've ever worked for that sells something online scrapes their competitors in some way (whether with bots or with interns).
Your argument is perfectly valid and applies to offline activities as well (what stops a competitor from walking through the aisles of a Walmart or Costco?), but this is a battle that can't be won, there are too many parasitic actors. It is human nature.