OnlyToday - 7:29 pm on Sep 18, 2008 (gmt 0)

...is it easier to ignore real and measurable limits inherent in your site and suspect Google...

The limits you list are real but not mutually exclusive with a suspicion. A suspicion is healthy, it is easier to deny the possibility of malfeasance than to face it. I'm not obsessed with Google's guilt or innocence in the matter. I'm simply not sure and do look askance at those who doggedly defend the mysterious giant.