It's for scripted columns mostly. The use case is like: "Let the scripted column generate data for all the items there are." Its not unlikely that the script is going to fail on one of many items. A trace-like output is quite helpful to determine what item caused the error in what situation - but as mentioned - you always need to review all of the output because the error icon will not light up if something weird happened.
I see and I agree, one needs to think about something sensible to determine when the icon shall disappear. To not over complicate things, two simple solutions come to my mind.
- Clear the icon when clicking on it (if console not visible, open it (as now), if it's already open, just clear icon).
- Clear the icon whenever the console opens or closes.
- Maybe combine 1 and 2. o)
The situation "When there is no error" as you suggest, is not so easy to determine I guess. o) This would only work in conjunction with an errorfree timespan or something, but that probably only adds unnecessary complexity here.