They are right to an extent. In fact, one can pretty much do a lot with just today's stock kernel minus even the low-resolution timers. This does not, however, nullify the need for a dedicated rt setup which by the way requires Ingo's patch. Take a look at it, and it's a huge bunch of change. This also means that more and more of his code is getting merged upstream so sooner or later we may not need a separate -rt patch, but that is not now.