You're implying (or assuming) that users who use terminals don't care about visual perfection or design or something. I'm not sure what makes you think that way, I certainly answer "yes" to your question about whether bleeding would bother me. We care about visual warts just as much as in other environments :)
Maybe I'm seeing it too much black and white -- CLIs vs GUIs, while there are intermediates like TUIs.
Why I think that way... I always had the feeling that people opting for CLI alternatives more look at the formal content, less so the way it is presented.
I prefer terminals because I can express my commands clearly through them.
I prefer polished UIs because they help sharpen my focus away from their flaws and into my work.
I prefer command line tools with polished UIs. I enjoy color highlighting. I run my editor in 256color mode.
I wish a restricted set of CSS was available through libncurses via ESC[ commands, with optional downgrade via term cap to Unicode characters like these one-eighth ones, so that we didn’t all have to suffer quite so much “UI is optional” default neglect from command line tool designs. (One that includes features for terminals newer than decades ago! Like tables, and borders :)
When I was using MS-DOS, boxes were typically done with line-drawing characters that are basically the same that can be used in terminals nowadays, i.e. with color bleeding. But then I learned that it was possible to avoid that, by creating some custom characters (still staying in text mode on an EGA/VGA) to have the lines exactly at the border of the character boxes. It was looking much better, and I still believe that.
Now, I'm not saying that my eyes hurt when I see boxes with color bleeding in a terminal. I've seen so many in years of TUI under DOS that I find them to be absolutely normal. But when I see a nicely done TUI, possibly in an unexpected or creative way, I find it more pleasing to use. It is the same as for a GUI: why not keep Windows 3.1 window decorations, if those details are not so important? The fact that it is in a terminal or not does not make any difference.
Aesthetics are medium-agnostic, they are valid both for TUIs and GUIs.
Yes, the content has less distractions and is more legible when it has solid uniformity and consistency. Bleeding colors create a distraction and may run up against other content, potentially degrading legibility.
Personal anecdote, I’ve spent half of my youth in turbovision-like interfaces and never experienced anything like what you described, never even thought of it before this thread. Not that subj is bad, but to me it feels like a strange problem to solve.
Same here for turbovision interfaces and similar. I've never found them bad. But when I've seen that an alternative was possible by changing the VGA character generator, I found that more aesthetically pleasing.
> it feels like a strange problem to solve.
Seen this way, why bother creating nicely-looking GUIs? It would be the same strange problem to solve.