It's really a western thing. Chinese like crowded pages with lots of functionality, they must feel very 热闹!!! The west prefers more distribution of functionality with simplicity so doing one thing is much more appealing to us.
Yes but not by choice. Besides, I've been to both Rome and Athens and didn't find either to be oarcicularly crowded compared to a Chinese tourist place.
I really think Google could have created the ultimate chat app... but I guess they are "creating their own competition."