One reason is that underlines are quite distracting when you have so many of them. Even Wikipedia avoids underlines for better readability.
Take the case of HN. The "15 minutes ago" and the username are both clickable for a topic. But not underlining or differentiating them makes the text more readable. Most of these things are opinions of course.
This would be so great!
Or to put it more clearly: There is not space for any "creativity" when doing the job proper means to follow the text-book by word. If those people don't want to "paint by numbers" they should try to make money with art. But there is no space for them in product design.
Form follows function! Point.
What's the problem? We want those people to get out of UI design because they're making things worse by trying to be in it.
Says who? If a standard had to be forced I'd vote for desktop on web over your kind of web any day.
'Comment#1':: There's more to UI design than disambiguity through explicitness.
'Comment#3':: Follows 'Comment#1' : Sometimes it's about things like simplicity
`Comment#2`:: Follows `Comment#3' : Other times, it's about things like removing redundancy, e.g. knowing a navigation menu is a special ui element and shouldn't be over-complicated with underlines, and changing colors. A navigation menu is not a text body which is usually against a simple backdrop like white, and is far more standardized. It also has do things like show child elements, which is what the whole article is about.
`Comment#5`:: Follows `Comment#2' : It's also about establishing brand identity that has a direct impact on market performance - like having custom color themes
Regarding the ellipsis, while it's true and recommended for menu items, this is not applicable to menu bars (or similar horizontally stacked items, like a bar of tab-options – mind that these are in principle just an array of buttons, as well).
Have you ever watched users try to interact with the web, their phone, and their desktop?
Many do not differentiate, and why should they have to? They all should be built using intuitive, unambiguous paradigms.
It might have been 20 or 30 years ago, but not any more, and Jakob's Law is as relevant as ever.
And obviously those aren't being used as menus or controls in the web app sense anyway.
Whatever navigates you to a different page is a hyperlink. Hyperlinks are underlined, blue or purple if already visited. Sounds boring and does not fit your favorite orange-lime color theme, I understand that. But that is also an actual standard users are used to. Desktop application have no similar concept. In Windows (Not sure about Mac) buttons or menus which open other windows should have ellipsis (...) at the end of in their name. For instance "File\Save" does not have one, but "File\Save as..." has one, because opens another window.
All texts in the examples are hyperlinks, but none are underlined and that is confusing in the first place. I do not understand why people do that. I feel like that should be prohibited, or at least considered a very bad practice. None have ellipsis either, if you follow Desktop standards.
Want to know if menu parent is a hyperlink? Easy, it is, if underlined. Period. No confusion.