The thing about the gaming industry is that want to retain players and keep more coming. That is always their goal. They will ban and eliminate those whose will cause issues that will likely cause a decrease in the majority of the community. Obviously data mining is a problem. But I've done manual calculations on my characters to see exactly how my DPS is doing before. It took me about an hour to access myself, whereas the parser would of taken 0 extra time out of my day. The parser would of given me zero information that I couldn't of gotten myself with some effort though. However, using it for grief tactics causes a toxic environment which makes players want to leave. Hence, why they work to prevent it.

No game will be 100% overlords about their every rule on the ToS. It's actually very bad business to do so. Even work places don't do that. Would you fire a great employee for being 5 min late once? No. You give them a warning at worst. MAYBE. More than likely, you don't bother causing a good employee to become jaded towards the company he works for because he was 5 minutes late one day. Why? Because it would be bad business in which the company wouldn't retain employee's very well. Does parsing hurt players? No. Do players who use parsing hurt players? Yes.

I hope you don't take the 100% rule for everything in life. If you're a christian and believe in the bible, you're very likely sinning due to wearing a polyester shirt.