Jose wrote:
I think the answer is fairly evident: Personal flying is not done often
enough by those who do it. This impacts proficiency.

I buy that.

Personal flying
often involves decisions which are made independent of the weather,
making the weather a complicating factor rather than a deciding factor.

But that's even more true of self-flown business flying. There are
lots of pilots who only fly for personal reasons that will only fly
when the weather is nice - making weather a deciding factor. Those who
fly on business rarely do this.

And since flying is expensive, it is harder to remain proficient.

True.

Also, people who fly for personal transportation often fly on longer
trips, which are not taken all that often.

But wouldn't that be just as true for self-flown business travel?

So, anything that rasies the cost of flying, or makes it more difficult
to accomplish a mission by flying, or increases the impact of weather on
flying, or discourages flying, will have a component that adversely
affects safety.

I agree. Thus all safety rules are bad - they do all the above.

Michael