This is "a site for software quality control experts..."

**Why** do most software-based companies seem to have a wall to prevent customers from submitting or monitoring bug reports, via support or directly to development?  IOW, rarely can customers submit bug reports that (even if 'good' in the technical sense) have more than a snowball's chance in hell of being communicated to development.  Why?  

If you are a software quality control expert, why do you think your/most companies follow this pattern?

(Feel free to disagree with my *rarely/most* claim, but my question is about the **why**; please read it as, "Why do **many**..." if that matches your perception.)

(I perceive that a wall is the norm, and it surprises me, and so I'm curious why things are this way and if it surprises others too, or if they've noticed it.  I had a hard time deciding where to ask this, and this board feels like a good match both technically, and in terms of a higher ratio of people who'll have good, interesting answers.)

(Added later:) 
Perhaps some examples would help?   

1)Here's a case where development can't communicate back to a customer: I found a bug in iOS, and I DID manage to communicate the other way - the bug I found was (I'm told) communicated, indirectly, to engineering.  Today, I heard that there was a new version of iOS, and I was asked upgrade and confirm that the bug still existed* - which indicates there's no communication in the other direction - just the support guy noticing that there was a new version of iOS. (Furthermore, I just realized, he apparently didn't bother to test to see if the bug was still reproducible before urging me to upgrade.)

*Well, even though Apple had, eventually, reproduced the problem, his request, verbatim, was, "confirm if **you** are still having the issue with siri and not being able to go back".  *(FYI: The issue was not being able to go back to see or edit what Siri had heard."  When I first reported the bug, the first tech said he was unable to **attempt to** reproduce the bug because he didn't have an iPhone that could run Siri.  He only had a virtual iPhone that couldn't run Siri.  He said there was no way for him to get access to a phone in order to attempt to do so, and when I asked to speak to someone who could, I was turned down initially.  But then I was transferred to a great (off-site?) rep who was willing and able to **attempt to** reproduce the problem on another iPhone with the same OS version in which the regression bug seemed to have appeared.  And he was **able to** reproduce it.)*