This site is not a scam. I submitted my private key and received my ETZ coins very fast.

Did not you think that Jaxx, Electrum, MyEtherWallet have access to your private keys too 24 * 7? Otherwise how can you extract your keys from them?

Only private key can prove you are the owner. How else can you get free coins? It's the only way. It's impossible to make money without trust.

This is a reputable fork. Otherwise all major wallets, pools and exchanges would not not support it. I always verify partners of the company and it's reputation before I submit my private keys.

I think the object was to secure the thing, not so much to overclock it.   They come shipped with admin/admin for the web interface with no way to change it, damn near wide open snmp active,  and no ssh access so you can't administer them enmasse very easily without remote command line access not to mention there is no way to shut them off remotely without ssh, so if you sent your miner to a farm for cheaper power or your away for weeks at a time from your miners and the price of BTC drops dramatically...people want a way to shut the thing off.
I believe I posted many days ago on the very subject of "why do you want to overclock it" and all the caveats with overclocking your asics, and also on the subject of "why do you want to take control of your fans" when the manufacturer seems to have gone through great lengths to keep very specific control on the fans.
But, some people want to overclock and mess with their fans anyway, who is anyone to judge them. Mabey they just want to play, learn, mabey they don't care about efficiency or lifespan,  who knows. It's their miner, they can do what they wish with it.