by your definition, anyone placing orders on the book is a manipulator because they are blocking the price from moving the other direction. who is a manipulator and who is not? if you place a 500 BTC sell order at $10k because you think the price will drop, that means you're manipulating the market now?
The manipulation techniques are essentially the same as with any other tradable asset out there, and they have little to do with what you describe here (read, it is not about traders placing orders - whales or otherwise)
Just in case, insider trading is also illegal even though it is all about placing orders in the way you mean it
A lot of project developer too are quite confused on how to curtail all these manipulation, some of them has even come up with the strategy of locking bounty hunter’s rewards, thinking they are the cause of the dumping going on and yet, it still has not effect, right now, I don’t think any solution will even come from an exchange because they are always the beneficiaries of these manipulation.