Why can you mine so much more of other cryptocurrencies with a lower hash rate? I have been researching bitcoin mining and one thing has stumped me. Why is it that you can you mine so much more of other cryptocurrencies with a lower hash rate? I've looked on cryptocurrency calculators and it says that 1 TH/s for Ethereum makes a profit of about $2M per month, but only $53 per month with bitcoin. If your hardware is capable of producing a high hashrate, why not mine a smaller cryptocurrency and exchange it right away?
Comparing hashes per second for Bitcoin and Ethereum mining is comparing apples and oranges. You can only compare hashes per second, if coins in question use the same hash functions for proof-or-work. Bitcoin uses double SHA256, which is a general purpose hash function and can be massively parallelized and optimized in hardware (ASICs). Ethereum uses Ethash, which is more memory-hard and mostly mined on GPUs. Zcash uses Equihash, Litecoin uses scrypt, and so on.

Miners who have SHA256-specific equipment can only choose between SHA256 coins (Bitcoin, Bitcoin Cash, Namecoin (?)). Miners with GPUs have more options, as many memory-hard hash functions are more or less GPU mineable.