1. Servers and casual internet users are one in the same, an internet user will play games and services with open ports to be excluded. The apps and various exploits would be different
2. Are you sure "getting too hard" is the correct term here? Most people are keeping exploits to themselves and don't want to share for free these days. They are plentiful and in abundance, you either have to pay for them or find them yourself.
3. Social networks are commonly stolen via SE, whether it be phishing, keylogging, browser stealing, etc. Also if running http which most dont these days and ssl strip doesn't work MiTM isn't as practical. Furthermore there are other methods of installing malware that doesn't require user interaction. Without physical access SE is the main route, other than that, a vulnerability in software they're running (java, flash for example) that allow remote code execution and drop a payload
You're only limited by your brain