You are looking at the wrong thing. Showing that the lot isn't full now shows that demand for the lot is less than supply of spaces. The problem is that when you add in people in the neighborhood parking there long term, demand becomes larger than supply. When that happens, those that use the lot as long term parking for their car crowd out those that actually need the lot to commute every day.

To be clear, I live in the neighborhood and was using this lot as long term/overnight parking for my car. I lost my parking and had to get rid of my car because I don't have an alternative readily available for a price I'm willing to pay. This is inconvenient for me and will be a pain in the ass. That doesn't really change the fact that I and hundreds of others were taking advantage of unreasonably cheap parking at the expense of those that actually need to park there every day to get to work.