If Joe Sixpack has a Mac, calls his ISP for help, is told the ISP only
supports Micro$loth, asks for escalation and can't get that (or even
doesn't ask for escalation) I would think Joe would move to another
ISP. Thus my earlier statement that the ISP which does this we-
support-Micro$loth-only crazyness is doomed to failure.
Perhaps that would be true if Micro$loth was a minority player in the OS
world. However, the facts here are that MS comes deployed on a huge
percentage of the computers in the world, and even if FreeBSD/Linux/etc
enthusiasts are wiping it off a certain percentage of those, Macs still
represent a very small percentage.
If the graphs at
are correct, we can probably draw the conclusion that less than 5% of the
installed computing base is Mac.
If we looked at Internet-facing browser usage,
suggests that this is a reasonable conclusion, with Windows making up about
90% of all browsing clients, 75% WinXP.
Further, in the context of the discussion, I don't really know if any ISP
is recommending Windows, but I know that some major ones won't even lift a
finger if you're using UNIX.
My favorite example is Road Runner, where I personally had the displeasure
of running into a situation where a UNIX VPN gateway was "dead" on the 'net,
couldn't traceroute beyond the first hop, traceroutes to it died in RRland,
and when I called RR support, they wouldn't debug it at an IP level until
I hooked up a Windows PC, which promptly DHCP'd a *different* IP address,
which (inconveniently) worked. Yet, at the time, releasing the DHCP lease
on the VPN box didn't result in a different IP address (strange RR DHCP
servers), so when the VPN box came back on, it got the same busted IP
address. The TSR took this as evidence that "UNIX didn't work" and
advised me that it wasn't a Road Runner issue, and refused to assist any
further.
Unable to make any progress, in frustration, I switched interfaces on the
VPN box, and bam, it worked. I pushed the issue a bit, later, and
eventually got a read-between-the-lines admission that that the problem
was something to do with RR having switched around IP blocks, but somehow
it was still the UNIX VPN box's fault for never rebooting or something
like that.
So they wouldn't even try to debug an IP level issue, which I would kind
of consider to be maybe... their core business.
Now, really, does anyone expect companies like that to assist with
problems that aren't even the core of their business?
Perhaps you think "doomed to failure" is a synonym for "wheelbarrows of
cash to be had." 
... JG