First, I wish I could be more constructive, but for me, this is the annoying little tip of a more critical iceberg, and I think that sometimes, showing your frustration can actually be constructive. Also, I would like to point out that my frustration is of course not directed towards Apple engineers (or any other person) but towards "the system/structure".
It is a convenience feature, sure, and stuff like auto balancing brackets gets into muscle memory after a while which makes it really annoying when it's sometimes there and sometimes not.
I do temporarily comment out code every now and then, yes, and I simply expect a professional IDE to be able to handle that without problems.
For example, I might comment out a piece of code while writing an improvement, or I might paste some code as a commented out temporary reference. Also, doc comments can include code examples, the standard library is full of them. (I do not, of course, leave (non-doc) commented out code in production code.)
If so, of course they should be mad at Apple and let both Apple and the community know about the problems and their frustration. They would probably ask if anyone else has the same problems and then, if necessary, spend even more of their precious time to isolate and formulate bugs.
There's no reason you can't get mad about critical bugs and irritated by long standing annoying bugs.
I have reported 103 Jiras and probably 100+ radars (found no UI to see the actual number), including some small overlap of old Swift bugs before Jira, and I'd not be surprised if that's more than what 99.9% of Swift/Xcode users has bothered to report.
I should probably adjust my tone, but the time I spend on bumping into, identifying, working around, filing and keeping track of bugs in Swift and Xcode makes it hard.
Well, this thread was my attempt. : )