reason for "no longer a dumb pipe," - is that I believe that was the 'defense' aka reason being used for a while to push back against different groups that were accusing and then trying to public shame cloudflare;
for protecting alt-right(?) I know there were a few PR pieces pushed in the UK or Euro press about some things - maybe hookers or something..
anyway for a while cloudflare was all like, we are just a really big pipe that pushes data and can absorb ddos.. we don't get into content moderation or opposite-net-neautrality..
there were complaints that some groups 'on the right side of history (or whatever)' - were trying to take down the stormer site I think it was and that their co-ordinated takedown attempts were failing as cloudflare was protecting the send/receive, being a pipe, not a judge..
This is what I believe ATT was using as a defense some time ago; they don't stop drug dealers from making calls they just provide the 'pipe'
There was also some groups complaining about cloudflare making it hard to find servers - to find jurisdiction, again uk /euro I think - I have those articles saved on one of my systems.. and may be linked to a HN comment long ago - where I said chipping away at this pipe thine will lead to a bifurcated internet - where we will have internet place X internet place Y - and companies like cloudflare may have to turn into a dozen different companies to keep up with the changing 'this speech is not okay' rules for various places..
funny how fast things can change.
I believe many of cloudflare's early customers especially felt protected and safe because of the stances - and I bet most don't know about the 180..
I also think most average web people would think if you set 'whatever' for your DNS - that the dns routing is basically a dumb pipe - it's not spying on you and sending copies of your data to gun agencies.
Just as I think most people would not expect their cell phone company or internet provider to spy on data and send snippets of your communications to agents. I would not expect my web server co to deep packet inspect all comms looking for bad things. (not without a warrant and being directed to look at a specific line, now a whole data center / cell co, etc.)
I think it was a terrible choice to make for cloudflare, but I know not an easy one either way.
So 'pipe' is a term that has been used in this way for a while now in similar fashion I thought - and it's not meant literally like a copper water line.
Also in some ways cloudflare has been a pipe - a pipe for flowing data that would be choked by ddos attack if were to try to send/receive across the net in most other ways kinda of.