Nope, most definitely not.

I actually saw a fistfight at boarding time on Tiger Airways in Singapore (WN-style boarding without the groups, so actually more like Ryanair-boarding) while I was there last summer.

Good stuff!

Thankfully, I have so far avoided the seatmate from hell, though I remember a flight FRA-ATL on Delta where I was seated next to a (very nice, granted) young woman (army wife, if I recall correctly) with a baby in her arms. But don't get me started on babies on planes...