Val mentioned in another thread about 'hothousing' with a negative connotation was bothering her; I've been thinking about that, too. BTW, I'm going to give personal examples, but I'm secure enough in my decisions that I don't worry if anyone disagrees with my methods.
GS9 has almost no homework. I hear other kids in his class take up to an hour/day doing homework; at least 30 minutes on the average. I give him nonfiction books to read for AR, often they correspond with a subject he's studying in school, I have logic puzzle books, Singapore Challenging Word problems, history books, etc., that I expect him to work in 30 minutes(total) or so most nights. Some things he considers great fun, other things he'd choose not to do if it was his choice. Is this hothousing, or is this teaching him how to apply himself to an appropriate educational challenge -- that he's not getting at school!
How about cultures where the children attend school longer than our 5.5 hour schoolday, and then go home and do more work assigned by the parents to improve their chances of getting into a university? Are they harming their children, even if the child would rather be playing video games?
If we have a spectrum with allowing a child to watch TV or play video games all the time on one end and at the other end the child is drilled constantly to memorize facts, I think we need to keep toward the center. And if your kiddo is coming up for some standardized achievement testing, I see nothing wrong with reviewing the concepts tested to fill in any holes that are easily filled.
