This article to me (as someone who's followed the whole thread and the discussions leading to that thread) looks biased. Or maybe it's because the otherwise thorough editor hasn't followed the entire discussion.
It started when Jes Sorensen sent out a mail about how best to expose performance counters to guests:
This lead to the following discussions about supporting perf across the host-guest boundary as well as having proprietary guests do their own profiling.
As a result of some discussions there, Yanmin Zhang posted a patch that used perf to profile a guest and host from the host when using the same kernel on both the systems (in the same thread, and continued in the two threads linked below).
And then to Ingo's suggestion about merging QEMU into tools/kvm, and how that would help development. And the KVM/QEMU folks on how that would fracture the QEMU community, with some input from folks from other projects as well.