In general not everyone has access to all code. Microsoft has over 90k employees not counting contractors. To get access to various projects/depts source depots you have to request access. Some access is auto-approved, for instance I am auto approved for devdiv and windows source access. Others require someone approving your access request. For instance, a few months back I was seeing a really, really annoying bug in Lync, I wanted to troubleshoot it since the repro was sporadic and I wanted to include an analysis in the bug I filed. It was the I found even getting access to non-stripped Office pdbs requires special permission, I applied for it and was denied :( Sometimes the bureaucracy baffles me.
BTW, it is really irritating that the MSVBVM60.DLL shipped with Vista and later and the VB6 ActiveX controls shipped with MS08-070 and later has no symbols on the public symbol server (MS had provided DBGs and PDBs for older versions of these in the past).
