I think it gives the impression that humans are almost rational, and only need to correct biases to become so.

That's why nobody should use a silly name like ‘Overcoming Bias’. (^_^) <g> :-)

Actually, I disagree. To me, ‘less wrong’ is a title of humility that suggests that we are wrong but need to become less so. In contrast, ‘more correct‘ would suggest to me that we are already correct but can still become more so.

Similarly, ‘half full’ sounds optimistic while ‘half empty’ sounds pessimistic, even though their literal meaning is identical. It's a matter of the emphasis to which the listener is drawn.

This may be highly subjective.