There is no damage to be done to a driver by hardwiring it (unless you try hard or are very non thinking). However, you need to have some skill and intelligence. I will have very detailed info on my website about this soon......including pictures.
Spade (disconnect) terminals are used mainly for convienience. Of course, those filled with fear will tell you they are there so you do not damage the driver. Some people and a very few manufacturers will solder to the tab on the speaker. However, do you want your dealer to come to a customers house to change the midrange on a Magico speaker and pull the driver out and solder on it?....dripping solder on the front of the speaker? No way, so you use a push on connector and degrade the sound. Best sound is your PC triple c wire soldered directly to the voice coil wire.
Clayton may be soldering to the tabs on the woofers in the Caladan speaker....as shown in a fuzzy pic of the back of the speaker. This will be known with a better pic.....No, he is not soldering to the voice coil wires (the other end of the tab).