We note this. We see that our seed was sent to the server every time that we changed. If the server have my seed, know how fuck me. This is fair? Every people can check this opening terminal of browser, in network panel, and see requests. 
Sending the client seed to the server does not allow the server to cheat its users. To get the result, Primedice uses a server seed, user determined client seed and a nonce. The results are hashed from the server and the results are sent back to the user. There is no practical way for users to not transfer their client seed to the server and still play the game. For it to work without sending the client seed, the server needs to send its unhashed server seed to the client. The client would need to then hash them and generate the result. Any attacker can also intercept the unhashed client seed in the process. This would then allow for users to cheat the casino.The results cannot be changed without changing either the server seed, client seed or nonce. Hence, before anyone start gambling, they need to randomize the server seed and take note of the server hash and client seed. They can then verify their results later.