Confusing use of あきれる in past-progressive passive

Question

This is from episode 9 of Dungeon Meshi, with the context of a person apologizing for insulting the following speaker's ill-commitment to take care of their axe:

構わん。 わしが鍛冶全般に興味がないのは事実だからな。 鉱石の見分けもつかず 昔の仲間にもよくあきれられていたものだ

It's fine. I got no interest in forging, so it's not like I'm gonna fix it. Some old buddies I had would always get on my case for not being able to tell the difference between ores. (show's translation)

I have difficulty understanding the use of 呆れる in the passive here because even if this is the "affective passive", 呆れる almost always has a negative sense by default and in the show if it wasn't passive it would be clear that the friends were dumbfounded at the speaker's lack of knowledge. Also I find it odd that it is in the past progressive because I had thought that 呆れる was basically an immediate reaction, as the English "dumbfounded at" implies as a translation.

Through this confusion I clunkily understand this as:

"My friends from a while back often used to be standing aghast (at the fact I cant distinguish ores etc.) on me"

Is my understanding correct and/or am I missing something about 呆れる, the passive or past-progressive nuances?

Answer 1

• 呆れる ("to be amazed/disappointed", see this for the nuance) is an intransitive verb, so you're correct that this 呆れられる is an indirect passive (aka "suffering passive") expression. His old buddies did the action of 呆れる, and it negatively affected the speaker.
• The teiru-form is not only for an ongoing action but for a habitual action. See: Habitual aspect. Here, ていた indicates that 呆れられる was something that happened on a regular basis in the past.
• ものだ also carries a nuance of recalling a past habit, often with a sense of nostalgia or reflection.

昔の仲間にもよくあきれられていたものだ。
(I recall,) my old buddies often used to be amazed at me.

The expression "get on my case" doesn't seem to be a faithful translation of 呆れる to me. If anything, 呆れる is closer to thinking "Oh he is hopeless".