WW - I profess as you have probably guessed already from our conversation the other night that I am a commuter racer! I suspect that the Uxbridge road is a clear, straight stretch which people can whizz down. I however, will always put safety first, slow down if hazards are coming up only to watch the idiots racing emergency brake and squeal down the road almost a fraction too late! Plus, don't see the need to RLJ to gain an advantage -it's pointless, though to be honest there is no point racing everyone. I think the post re recovery and training rides may sometimes apply as well as people may be training on their commute (not always a useful strategy in London with the many stop starts though but all those PB times to beat -lol). However, I do agree that the close passing and overly aggressive behaviour is not necessary and can be very unsafe. I've never passed too closely unless someone has moved into my path without looking behind them and do try to be considerate.
Commuter racing can be a real fun part of the commute if done with care and consideration to other road users!
For the record WW - you're pretty fast...just get some drops bars and you'll beat em all soon -hahaha