We walked around Leicester Square and Soho around midnight in July. There were so many people on the streets. Why does the guidebook say there is no nightlife in London? Maybe the guidebook is comparing London to Barcelona, one of those cities that people party until 6am.
Restaurants and bars were open and people were eating late. There were also street performers. Even after midnight, the crowd was still large and showed no sign to die down. At least that's the case in summer, I don't know if it's still like that in winter. This area is way bigger and definitely more happening than Santa Monica Promenade, where the crowd is half gone after 10pm and only few people lingering after 11pm.
Too bad this tourist needed to go back to hotel to sleep. Going to a London club was not on my itinerary.
Central London is very safe for tourists. During this trip, we walked around West End at night and walked back to our hotel which was also in West End, we never had any problem. I really appreciate that. But I wouldn't push it and walk alone at night, better safe than sorry.