I'm not really sure why people do not use PIN to drive. It just seems a no brainer to me and takes less time to activate than putting a key in the lock of most cars. The only negative point if you have a car full of people that you may not want to disclose the PIN to, but there are other slightly less easy ways to avoid the need to enter the PIN in front of a car full.
I'm one of those people that doesn't as a day-to-day feature. I don't see the point as in my view (and my personal experience with theft), it won't actually make my current configuration any more secure based on my current driving habits. But it's horses for courses. Some areas are safer than others, and people have gone through different experiences of theft in their lives.
That being said, I have a road trip planned in May, and I will definitely be activating P2D, and deactivating any other convenience features for entry and drive.
Overall I think the Model 3 has enough of a feature set to make the car secure for any owner in any circumstance; as long as the owner knows what they're doing.