Computers irritate me. Long ago I searched for the ultimate nirvanic computing experience, though I have long since resigned myself to being irritated
less.
The source of the irritation, I believe, is that computers are designed by people. Ordinary people. People like you and me (well, not like me. I wouldn't have made some of the fartblastingly stupid decisions that they have, but there you go).
The thing is, ordinary people come up with things like this:

Is this a problem? An inscrutable title, meaningless buttons, and a half paragraph of exposition? Is there a problem here? Many would say "This isn't unusual at all," and you would simply be avoiding the question - familiarity doesn't eliminate problems, it just makes them easier to ignore. The cumulative effect of poor design is an overall poor experience.
What pains me is that many such examples are actually not very difficult to solve. Twelve seconds of effort on my part produced the following:

Not particularly extraordinary (and not without it's flaws), though immediately clearer and easier to understand.
The problem, as I said, is not that these issues are difficult. Rather, it is that they are not being addressed correctly, if at all. The design decisions for each of these simple interactions with the user are falling into a black hole, and are dragging us simple users with them.
Needless to say, I am still irritated.