Particularly if you're physically imposing you run the risk of a panicked officer pulling their weapon..
As for the 'handcuffed trip to the station', that's never happened to me, and I've done it close to a dozen times. I've also never ended up with a ticket while doing this.
What kind of backward country do you live in where you're not free to move around police officers if you're not actually being arrested and you're not threatening them?
Whenever they pull someone over, which is often, they have to judge what you're going to do. For them, the chances of you doing something crazy like speeding off, pulling a gun, etc. is not insignificant. That's what they're thinking about when they're walking up to your car. They've been trained about what things to look for. And getting out of your car is the way many violent interactions begin.
If you just get out of your car and act nice, I doubt it could really be a problem. It's just a dicey thing to do, making any sort of act that could be perceived as aggressive towards an officer.
And getting out of your car is the way many violent interactions begin.
It is, which is why you remain polite. It's not going to work if you're angry. It does (usually) change the way they talk, since on their part you now need to be managed, which means not going on a power trip. Remain friendly and they won't fear for physical safety, and you're now in a conversation where you're much less a submissive.
You have been very lucky to get reasonable officers. Most I have talked to (or seen in media / documentaries) have been trained to escalate with force if you are not submissive - get out of your car leads to "GET BACK IN THE CAR NOW HANDS ON THE WHEEL", answering back ("Why? I'm doing nothing wrong") leads to verbal escalation/shouting, shouting yourself leads to handcuffs, resistance (even passive) to physical force or (according to media accounts) tasering. Granted my sample size is potentially biased, but I thought this was the norm. On the other hand, when I've been relaxed, calm, and collected while remaining in the car I've had no issues and otherwise pleasant conversations with officers.