If registering my trade name does not give me ownership rights, why should I bother with registering the name at all?

Registration is not required in order for you to own the trade name and you do not therefore have to register the name. The advantage to registering your trade name is that you provide notice to others that you are claiming the rights to use the name. The second advantage is that the registration process may let you know about any other person who is claiming the right to use that name. And if your name is registered, those who seek to register later will have notice of your claim. In either case it can help you avoid legal disputes which may be expensive and disrupt your business.