My 10 yr old sister walks my 7 yr old daughter home from school sometimes... The entire staff at the school is aware of it and I've never had anyone tell me it's not a good idea.
I feel like there must be more to it... Or I'm just a shitty parent...

I think that ten is a reasonable age for children to walk home, I would never send Hayden out by himself, not even Javen. But they are 4 and 7. At ten the child should know how to get home so that they don't get lost, be aware of watching for traffic and understand not talking to strangers. Kids need to learn how to be responsible, and if they are responsible I don't understand what the big deal is.