The comparison is not quite the same. The average Joe does not need to study a course to understand why one ISP is less reliable than another and why an outage is occurring.
That comment is like saying I should blame Ford if my car is held in a traffic jam caused by road-works. You clearly have no understanding of how either the internet or business works.
Most people want a quality service for the money they pay. TalkTalk has had a bad reputation over the years as an ISP and if the outage was a fault from Openreach or a fault in the cabinet then it will be understandable that blaming the ISP in this case wouldn't have made sense. But like you already described the service outage occurred with the ISP but not with the local exchange.
It appears that a more expensive ISP does not always necessarily equate to a more reliable service. Hence why I didn't sign up to a more expensive ISP. Now maybe I shouldn't have gone with TalkTalk exactly, but I certainly wouldn't pay £40 a month for an 80/20 Mbps package because a) that's not very rational and b) it doesn't promise me a more reliable service unless it was FTTP.
I'd be fuming in your position if I paid £38 a month to IDNet for 80/20 Mbps and not receive a specially better service compared to £21.95 with TalkTalk. For example FTTC is always going to be naturally less reliable than FTTP regardless of how reputable the ISP is. I'm not obliged to know how the business works, when I pay for a service I must get the service I am paying for or otherwise I will feel ripped off.