the very notable difference is that when you make software for a company, you're creating something thats supposed to be used by other people and getting paid in return. if you sell someone a crappy homemade mattress, and charge them 4 weeks at $80/hr, you've basically committed fraud.

if I make a mattress, or a mug, or a shirt, or a skateboard for my own use and it turns out badly - i've learned something and probably enjoyed myself.