This just means that the forum has more users than the others, and is not necessarily a measurement of quality. Quantity is not quality my friend.
Yes, I know that thank you for enlightenment
< ... >
Where did you get those stats? I did not see stat source in OP.
I took snapshot at exact time of all 3 forums,
and as I did not want to advertise other forums I simply posted respective names on images.
Since PIE charts are the most common and one of the most intuitive charts to read, here are the distribution of bitcointalk ID's from 1 to 2'000'000 .

Cool! Thanks for showing this.
That is why I wanted to add graphs for active users,
as I dont know if other forums have ranking system.
Update:
- Added
'Users Online'PS
I was also wondering:
- Where do ex-bitcointalk banned users go after ban? 
- Is there bitcointalk
heaven ,
hell and resurrection ??