What are rules for?

Why do people don’t follow rules? what are rules for, if people don’t follow them.

So Today, when my wife, Vicky and I arrived at the Victory Height tennis court to play tennis, I met  two individuals playing soccer tennis on the Victory Height tennis court. (Soccer tennis is using a soccer ball and kicking the ball back and forth across the net and court). When my wife and I address the individual and asking them, if we can play tennis on the court, they told us they just go there. I then ask them if we can use the court because they can play soccer on the large grass field and we can only play tennis on the tennis court, they then told us they will be playing for another 30 minutes. Then a young 7 year old kid nearby pointed out the posted court rules which states that the “courts should only be used for tennis and other city approved activities”. I then address this to the individuals playing the soccer tennis and they argue that their activity was a city approved activity and would not leave the court. I complained and stated that “that can’t be right”, since it is stated that it is for tennis only and they don’t have any written statement from the city therefore it is not approved.

My problem is this, if I was in their shoes playing soccer on a tennis court when someone shows up playing tennis, I would yield the court. Instead they call me grumpy and saying that these are rules and not laws and that it can be bent or broken and they are not meant for them.

So my question is Am I wrong for following rules? What is the point of posting rules stating that the tennis court is only for tennis and people don’t follow them?

Is this just Seattle? or is it just me getting old and grumpy?