Again, PBmining could dispel all rumors/doubt by simply providing a mining address. Why don't they?
Because they're clearly satisfied with how their service is turning out and doesn't feel the need to please everyone that's screaming ponzi? 
That makes no sense. Why would you purposely turn away potential customers?
If there are so many people screaming ponzi, wouldn't the logical response be to prove you are not a ponzi?
Why would PBmining spend so much time/effort implementing a complicated coin mixer AFTER people begin the ponzi accusations?
Did Mr PBmining wake up one day and think to himself "how can I make my company look much more sketchy and make it much harder for me to acquire customers?"
PBmining could be massive if they would have just proved their legitimacy 10 months ago. I'd guess they could have more 10PH/s by now if they didn't limit their customer base to gamblers and gullible noobs.