And higher hashing power is more secure. The higher the hash rate the harder it is for anyone to pull off a coup of the blockchain.
This is not correct. If you hand mining over from a decentralized system of tens of thousands of GPU miners to one ASIC manufacturer it does not increase the network security.
For this reason we need to change the hashing algorithm from time-to-time, so that no ASIC can be produced (ASIC production takes a lot of time).