If you use smart email security practices, you won't get caught in those phishing scams. Neither my eBay nor PayPal account have ever been compromised. I always check the links in the emails I get to make sure they're legit, and if I'm ever in doubt I just go straight to PayPal or eBay and login.
Another reason that I didn't like it was that I log in from different locations, I could carry it with me but sometimes I have someone else log in and then they wouldn't have the key.
Yes they have a back up to get around the security key, but when mine gave out the stupid backup system gave out too.