Jann Wenner, founder and publisher of Rolling Stone magazine loathed Rush with a passion and wanted his magazine to have nothing to do with them. It was truly a "hell freezes over" moment for the band to finally grace the cover.
...which really didn't explain all the hate - but I had an "inkling" ('We are the priests of the Temple...'), which was confirmed by this comment:
Around the release of 2112 RUSH was labeled as Ayn Rand right wingers by established "critics" and leftists like D. Wild. A. Rand did have a profound effect on Alex, Geddy and Neil in paticular. They were three young, idealistic, ambitious, highly creative individuals open to new ideas and finding their own path without compromising their values or integrigty.
The perception of RUSH as right wingers foisted upon them (40 years ago!) will never be forgiven or forgotten by any leftie, regardless of talent and unmatched musicianship and more importantly, all three are quite liberal, while Neil does refer to himself as a "bleeding heart libratarian".
Rock used to be about rebelling against the establishment, breaking traditions, etc...while lefties like Wenner, Wild and HUNDREDS of other self described left leaning critics over the last 40 years have trashed evreything about RUSH, they are now the old guard, the so called establishment. I believe this is the main reason why RUSH has never been accepted by the "mainstream" critics.
Now everything is clear...