Agreed, but to be fair, you guys are a small minority within a small community that has self-selected itself on the basis of an interest in self-build that goes far beyond that of the ordinary person having a house built or renovated. I know a handful of people who've done large refurbs (double house size sort of thing) and built from scratch, and every one of them looked at me blankly when I asked what sort of insulation they are using (I didn't even bother asking about U values or airtightness).
I was unhappy with our first architect. Not incompetent, but we didn't like what she was designing us, and the way she positioned the house on our block would never in a million years have passed planning.
I'm hugely positive about the architect we replaced her with. He had great ideas, was technically excellent (with the possible exception of some of his weathering details) and really helped us think about how to approach house design. We would never have come up with the layout he suggested, but it works really well in practice. There are, of course, things I'd change in hindsight, but they aren't his fault. Design is an organic process, with lots of compromises, some of which aren't apparent until you're living in the space.
Friends of ours had a highly awarded architect design them a house. It's a hugely contemporary glass thing to sit on a country plot. They've just had it costed, and the cheapest he's been able to find so far is over twice the budget he gave the architect. To be fair, I do think they (the friends) were ridiculously optimistic on price and indeed may have contributed to the higher costs based on their insistence on luxury spec throughout. It's also a difficult house to build, and I know lots of builders simply refused to quote.
Other friends of ours used an architect to convert their bungalow into a two story house and are wildly happy with what he did.
So what does this tell you about architects? Very little, I suspect. Like any professional qualification, it's just confirmation that at some stage you ticked all the boxes to get it. How good a practitioner you subsequently become depends on your talents, experience, motivation and a bit of luck. You should expect competence, and for most people that's sufficient (see first paragraph above!)
If I found an error, I'd point it out to the architect and have them fix it. As you say, the "correction" isn't my responsibility.