A chihuahua is a dog. Dogs have an instinctual drive to patrol with their 'pack' aka you. This translates into modern terms as taking the dog for a walk. If you don't want to walk a dog get a cat... just don't get a Siamese, they think they are dogs when it suits them and it suits them when you leave them behind.
Yes, you can get by with not walking them everyday, but you will get more behavioral problems. They won't get enough mental or physical activity to help them be stable and happy. Even 20 minutes just around the block will help balance them out. They are small... but they are ACTIVE and small.
Mine gets 30 minutes to an hour.. depending on weather. And playtime as a plus on top of that... we play fetch and 'find the biscuit' and 'dog runs madly in circles barking while I point and laugh' and other stuff. If I don't get to walk her she gets tetchy and misbehavior is had. IE she barks madly at nothing lots.... and your dog will be bigger then mine... so yup.
@ shawtiee I get that sometimes if we have gone to one of the bigger parks around here. I never thought of her trying to say she was getting bushed...
I will have to see if she wants held next time she does that.