I think humans and Time Lords are... damn near exactly the same. Time Lords have much more power than us, but their emotional behaviour and lifestyle structure is pretty much an exact replica of our own.
Humans are as corruptible as Time Lords if not more so but you are forgetting everything is NEW to us. That's why he has human companions. We also seem to be more compassionate and more likely to help complete strangers.
Time Lords are basically bored rich people with manners and most humans are not bored rich people with manners.