Why would you keep a pet if you don't have time to take care of it?

My neighbor's dog was often left alone for a few days because of his work. He doesn't have anyone to look after her, so he would just leave food and water that wouldn't even last for a day. Then one day, the dog sneaked into our house's backyard. Her fur was rough and she smelled really stinky. I fed her that day, and she came back the next day. I met the owner last week, and we talked about his dog. I told him that I'd feed her if he wasn't around. The dog became accustomed to me and would wag her tail every time I gave her food and water or called her name. I wanted to bathe her, but I guess that's over the top. I feel really bad. I wish she had a responsible owner. 😩