Just because a group of people say something doesn't mean it's true. It also doesn't mean they are wrong and/or that you can prove them wrong.

Me? I'm not saying it can't be done(out loud anyway), but I don't see melee working in arenas well at all. That shouldn't stop you from trying it if you want to. I encourage you to prove me wrong and I hope you do. In the pve aspect the only fights that I could see give meleers a problem are ones that involve a lot of movement. I wouldn't be surprised if you could get far in pve with meleers, but I would still say they are worse off than other classes without proof. Again, feel encouraged to try and prove me wrong.