Exactly. Business traffic is business traffic. There is absolutely no reason that a "consumer" grade fat fiber pipe is unusable for non-critical business stuff, except for one reason:

"We can charge businesses more".

But hey, I guess little shops that want to provide their customers with wi-fi and batch send some financial information at the end of the day need Big Expensive Solutions (TM) to accomplish it...

As a former pawn in the ISP game, there's a lot of reasons, though most of them are either directly or indirectly related to SLA's. The implied notion is that residential customers aren't going to lose money while their connection is down, whereas most business customers lose money every minute that their connection is down.

When I was in residential support, you don't know how many times I heard, "Well you better get this fixed ASAP! My business depends on it." I'd have to remind them that if they expected business-class service -- including 24/7/365 phone/email tech support, over-nighted equipment replacements, etc. -- then that required a business-class contract. If you pay the pithy rate for consumer-grade service, you get <surprise!> consumer-level support, and there is a world of difference between residential and business support capabilities.

It's also not a secret that the business support techs are usually a rung or two above those in residential support, and so what may take that junior-level tech a few hours to fix, would take the senior-level tech in business support a few minutes (and more often, to resolve it correctly). This is not only due to the nature of the issues being more challenging for business support, but because it's the ISP's prerogative to keep their clients online. Unlike most residential customers, business will more likely have access to more options for service; whereas AT&T, Comcast, TWC, etc. can piss all over their residential customers, it usually doesn't matter because the customer literally has no other alternative. On the other hand, businesses are often courted by ISP's, and competitive offers are always available. This is compounded by the fact that business-class service more specific in its offerings; you don't just pick a "basic" or "turbo" package, you often have 10x as many choices which take into account latency, burst rate, symmetrical upload/download, etc.

Another perk of business-class at some ISP's is a direct communication line to the NOC. Not specifically by phone (still have to go through support for that usually), but at least where I worked, the NOC sent out emails to our business customers for every planned outage (in advance, right before execution, and upon completion) with details of the work, as well as for unplanned outages (which usually detailed the nature and impact of the outage). At times, alerts were sent out when a large-scale malware, DDoS, etc. was present. You know, things that as a business, your own networking/sysadmin staff need to know to do their job effectively.

When I see comments like this I thank my lucky stars I'm not slanging DWDM/Fiber anymore.

I've said this before but it's worth saying again: In the United States we have two classes of Internet. One is the consumer net, which is quasi-3rd world in many parts of the country. The other is the Enterprise, which is, I would argue, the only first-world network on the planet (by aggregate capacity and availability).

When you subscribe to the former, and expect the latter, you'll undoubtably be an unhappy camper.

None of what you wrote is an argument for banning users from running servers on their Fiber accounts.

In fact, it's almost insultingly paternalistic if that is in fact the view Google (or any other ISP) takes.

That's because it wasn't an argument for banning users from running servers on their Fiber accounts.

I was responding to the parent (perlgeek), not the original submission. It was an argument for why business-class services exist, who might require them, and the value they bring.