There are other reasons too, but that's the main thing. Dogs are always up for playing. The other day I was stuck at a traffic light and watching this guy walking his dog down the sidewalk while he was totally absorbed with talking on his cell phone. The dog meanwhile grabbed a hold of the leash with its teeth and was tugging on it, trying to get his owner into a game of tug of war. And the dog wouldn't give up. He ran all over, trying different angles. Nothing worked but he never quit. If he could talk he might've said, "Get off the phone, you mope, and let's have some fun!"
And dogs are good sports about playing. They make no demands as to what sort of playing there is to be done. Like the dog with the leash. They'll create ways to play. Fetch. Winging a Frisbee as far as you can. Squeaky toys. And they're game even when we stack the deck against them.
I used to have a Golden Retriever named Dustin, and he loved to play with a tennis ball. A tennis ball. Then one day a tennis-playing friend came over with a tennis hopper filled with maybe fifty tennis balls. Well, I spilled the hopper all over the floor and poor Dustin was overwhelmed with trying to control them all. I know it was kind of mean (but a riot to watch).
And dogs like to play with each other. I remember being at house for sale. I was looking around the house, and then at a sliding glass window I saw a playground set and a huge dog romping around. It was a Great Dane and when I looked closer I could see that it was playing with a tiny little Chihuahua! And they were having a ball, running around, chasing each other. (Eventually the Chihuahua got a little tired and hid under the slide to get a breather!) It was so encouraging to see, especially since the the Chihuahua wouldn't have been much more than a bite-size snack for the big fella.
And so that's why I like dogs. They are the most playful animal on the planet!
