All the time I'm sitting there at a stop when someone pulls up and stops with no stop sign, then honks and waves at me to go on. No. I have a stop sign. You don't. I am not going. The last thing I need is to get half way through the intersection and you plow into me and claim I ran a stop sign.
No. Follow the damn law. If you stop first, you go first. If I have a stop sign and you don't, you go. If we stop at the same time, the person on the right goes first. It's the fucking law. If you can't figure it out, go back to driving school. Don't wave me on, because the cop and the insurance company don't take much stock in "waves". They expect people to follow the damn law.
It's not defensive driving. It's dangerous.
Of course I don't really like 4 ways in SF where you have to fight tooth and nail for your right of way, but some happy medium where everyone just efficiently goes when its their turn would be nice...
A good percentage of the time two people end up trying to enter the intersection at once because hand signals are not a clear communication method for signaling right of way.
There's all kinds of legitimate reasons you might be uncertain about who actually has right of way (and, even more so, have doubts about whether other drivers perceive the situation the same way, and agree with your perception of who has right of way.)
"When in Doubt, Bail Out" is actually the NHTSA gives to this situation, and emphasizes that it trumps all other intersection right-of-way rules. [0]
[0] http://www.nhtsa.gov/DOT/NHTSA/NTI/Article/RightOfWay/RightO...
There's no such thing as merge, there is only shove!
Edit: No blame devolves to you. As I said, it's a cultural thing.