I addressed that argument before too. If I walk by a stand, say in Jurassic Park, and the line is 8 people deep, I can either join the line or walk by. If I join the line and someone requests water, then the water request will take about half as long to fulfill as a full paid transaction. Therefore, my line wait will be shorter than it was when I expected that all 8 people would purchase something. People who are getting in line to order something want to order something and the difference between 5 people and 6 people in line won't make a huge difference in their decision to wait. They can also continue walking to the next available stand. The number of available stands far outnumbers the number of available Freestyle machines. Additionally, the people waiting in line are prospective buyers. Freestyle guests have already spent the money and should be able to access the product that they purchased.
Ultimately, I think your argument is that you don't want to wait in line for water when there is a self-serve option available and the argument that Freestyle guests are making is that they don't want to wait behind people who are freeloading off the system. The guest that has spent more money is going to win out every time.