Unless you’re willing to modify the chassis, run raw speaker cable internally, and direct solder to the exit points of the output stages, you’re going to be dealing some compromise in SQ. Each termination point introduces an additional "relay," contact point, inferior material, etc. into the signal path. But, us "consumers" want the convenience and flexibility of connecting things "easily."
While there is nothing "wrong" about connecting raw cable to speaker terminals, it’s not very convenient to do so, but certainly more convenient that direct soldering internally. And, depending on the number of predicted connect/disconnect events you see in your future, a direct connection (to the speaker terminals) may, in fact, be the most efficient connection method. The time spent terminating a cable so that it will be convenient to disconnect/reconnect later may be more time (and money) consuming than just connecting the cables directly IF you don’t foresee the need to move the cables for any reason.