Playful & Couch Potato Traits

So I made a dog who I intended to be lazy yet playful, but even though I CAN do that, it really doesn't work at all in practise. Even with the playful trait he cannot play due to the couch potato trait. So these traits contradict each other huh. I personally don't see why a lazy dog couldn't play at all but sure, okay - more disturbingly what I don't understand is why are we even able to choose both traits then?

I'm going to remake and replace the dog probably because now it basically doesn't have a third trait. Just saying that this wasn't a very nice thing to find out after already raising the pup...