Paypal is basically anti-gun, which turns a lot of people off right there.
Paypal's dispute resolution policies can be questionable at times. I know of somebody who sold a fairly expensive knife and the buyer used Paypal. The seller mailed the knife Priority Mail with delivery confirmation. Buyer said he never got the knife, even though delivery confirmation showed the package was delivered to the proper address. Buyer filed a dispute claim and Paypal sided with buyer(who more than likely got both his refund AND a free knife).
Myself, if Paypal wasn't so convenient, I wouldn't use it. But, until there's a better alternative, I'll sheepishly tag along with Paypal.