250 years. We've had a form of First Past the Post for as long as we've has government, and mathematically that always results in two parties, aka lesser of two evils. Without changing that, we can point fingers of blame wherever, but the people don't get a real choice.
I wonder if this sticker is on the car of someone who always voted third party or abstained? Clearly, since it's "you" and not "us", so not taking responsibility for generations of voting. Do they realize that their choice might have caused this outcome too? Probably not, since they're using a bumper sticker to blame everyone else.