|Discrimination against pit bulls so bad that four iterations of the breed appear here|
Racism in any form is intolerable enough, but to have it so blatantly incorporated into a routine business transaction shows just how far we still have to go to achieve true social justice in America!
Obviously the reason having one of these breeds as a pet increases a person's premium is because these are the breeds at highest risk of causing liability claims against their owners. If it was due to some irrational anti-terrier bias on the part of Geico, other insurers could undercut the company by offering people with these breeds lower premiums. It turns out that this is standard practice, though, because, well, because that's exactly how the insurance market works most efficiently, by basing premiums on risk profiles.
"But isn't the real question how their owners raise them?"
That confuses cause and effect. It's not that people who want aggressive dogs tend to get pits and consequently pits become aggressive, it's that pits inherently have an aggressive temperament (especially towards other dogs) and the capabilities to make that aggressiveness count that lead people who want aggressive dogs to get pits. Blacks aren't fast because they play cornerback, blacks play cornerback because they are fast.
"But labradors and collies bite, too!"
Not as frequently as rottweilers do, and perhaps even more importantly, if a lab bites at your toddler or your whippet, you might be looking at stitches. If a pit bull does, you could be putting down your pup or burying your own baby.