Wetherspoons or "Spoons" (or "Wethers" ) does attract a number of "gentlemen of the road" as you say (inevitable when in most other pubs a pint of decent lager is now around £5.60!).
But it is also a haven for the young 18+ crowd (and those that manage to sneak in under the radar - difficult but don't underestimate a 17 or even 16 year olds ingenuity...however I must say from the tales my boys have told me their door staff are on the ball and seemingly more efficient than the old East German Border guards so it's a rare occurrence).
Before going to Uni the Balham and Wimbledon "Spoons" were THE meeting place so this will come aas a blow when they return in the holidays!