Hi Q,
Those are faston connectors, and they are an industry standard and used in just about every speaker out there. I have never come across any production line manufactured speaker that actually soldered the connectors to the driver. Doing so would be a logistical nightmare, dramatically raising costs with no benefits. When it comes to resistance, we are talking about thousandths of an ohm here, immeasurable and having zero effect on performance.
You can attempt soldering the leads if you like, but unless you have serious solder skills - you will heat up the tinsel wires on the driver and potentially cause permanent damage. I don't recommend it.