"You say it's important to overcome biases. So isn't it hypocritical that you're not trying to overcome whichever bias prevents you from realizing you're wrong and I'm right?" — everybody

Correcting for bias is important. Learning about specific biases, like confirmation bias or hindsight bias, can be helpful. But bias arguments – "People probably only believe X because of their bias, so we should ignore people who say X" tend to be unproductive and even toxic. Why?

1. Everyone Is Biased All The Time

You could accuse me of having a conservative bias. After all, I'm a well-off straight white man, a demographic well-known to lean conservative. If a liberal wanted to discount everything I say, or assume any conservative arguments I make come from self-serving motives, they've got all the ammunition they need.

Or you could accuse me of having a liberal bias. After all, I'm a college-educated atheist Jewish psychiatrist in the San Francisco Bay Area. All of those demographics are well-known to lean liberal. If a conservative wanted to discount everything I say, or assume any liberal arguments I make come from self-serving motives, they're not short on ammunition either.

This is a general phenomenon: for any issue, you can think of biases that could land people on one side or the other. People might be biased toward supporting moon colonization because of decades of sci-fi movies pushing space colonization as the wave of the future, or because Americans remember the moon landing as a great patriotic victory, or because big defense companies like Boeing will lobby for a project that would win them new contracts. Or people might be biased against moon colonization because of hidebound Luddite-ism, or an innate hominid preference for lush green forests and grasslands, or a pessimistic near-termism that rejects with payoffs more than a few years out. I personally might be biased towards moon colonization because I've been infected with the general Silicon Valley technophile mindset; or I personally might be biased against it because I'm a Democrat and Trump's been the loudest modern proponent of more moon missions.