You might be the kind of person who does benefit from accessibility features such as larger font size. On the other hand, I'm not; I can read 10pt font on 100 DPI display just fine, without glasses. I'd rather have an extra column in table view visible without scrolling than larger letters, but for you the tradeoff might be different. That's why it's accessibility and not usability. Usability would be if the bigger font didn't push anything off screen, then of course it's better to make it bigger.