please note, i am not forcing it on people and stating that london is the place for street photography. what i'm saying is that,
for me, there are countless more photograph opportunities when it comes to street photography. it can be because of reasons, i can only guess at them. who knows how my mind works? i don't even know, do you profess to know?
things like:
1) the fact that while i am residing within london, it is probably going to be only temporary, the mentality and approach is going to be different
2) the fact that while the police there are given powers to harass photographers, the general culture is to ignore, rather than to confront. i have had 1 sole confrontation even when i do street photography much more extensively there; in the numerous holidays and shooting in singapore, i have encountered at least 5 occurences, when i only dabble in it.
3) london buildings are for the most part, closer to each other. it is far denser in terms of building. i love light, i like to use it when shooting street photography. i am not interested in capturing a journalistic view of things. because of the layout of the city, it is much more conducive for that sort of photography.
4) singapore is cosmopolitan to a degree, london takes it way further. other than the mixture of people, races, there are also issues like seasons, the manner of garb is much more fluid and varied. that is a fact.
these are my reasons.

i have a london thread in the streets and candids section, i am curious why you are still asking me to double post.
much of what i see from singapore "street photographers" (self proclaimed) are just snaps of daily life. that, to me, is not street photography. something like what i see in HCSP and ESP in flickr, something that says something - and not just random snapshots that were taken with bokeh, or just given credit because "wa, you got balls to shoot like that"... that doesn't excite me.
perhaps it is because i grew up in singapore, much of what is seen here has become mundane to me. i acknowledge that i am not being entirely objective here. but i know my point of view. and no one needs to take mine, because i am not trying to shove it down your throats.