I've seen that argument, and while I agree it's true, you can adjust underlines with CSS and links can be "hidden": behind human readable text anyway. I really do get the argument but it's easily skirted and is an edge case or minor problem at best.
Yes. This is true. But you can't decide where your links end up. If I put your link on my site and I have text-decoration: underline on my links it will be harder to see the underscores.
I've seen that argument, and while I agree it's true, you can adjust underlines with CSS and links can be "hidden": behind human readable text anyway. I really do get the argument but it's easily skirted and is an edge case or minor problem at best.