Going to the parks in the morning and using what was meant as a party ticket inclusion to avoid the parking charge for earlier in the day. It can't be more clear. You are correct about the fact that there are 3 separate hard ticket events causing the parks to close early during my stay. It's overkill because of the $$$ it makes Disney and wrong to charge full ticket price for a day then close early just to sell more tickets for the evening. If you closed at 6 or 7 on non-party days it would be a different story. This however, rarely happens.
However, the larger point is that this is not what is meant by the offer of free parking FOR THE PARTY. I remember those who parked at Downtown Disney in Orlando and took a Disney bus meant only for resort to DD use to avoid paying for park parking. Guess what, Disney got tired of it and made transportation changes that were horrible for everyone to keep this from happening.
When the use of free parking for the entire day instead of as intended as an inclusion just for the party becomes realized as a loss for Disney b/c so many people are doing it, the benefit will be lost for everyone.
That's my issue, one that most people are against, "stretching" the issue until it is lost/worse for everyone.
I am not faulting anyone for trying to stretch their dollars, I do it as well, i just try to be fair applying things in all situations. I won't trouble you further with this, even to say i told you so when the free parking inclusion with tickets disappears in the future, just for this reason.