I guess people who design bridges are not "real engineers" because so many bridges have been built before and they are only plugging together load formulas that someone else came up with.

We're talking about a hosted blog, ie., creating an account on WPEngine or similar and sending the credentials to the user. If there was a similar service for bridge building ("choose two points on a map, swipe your CC, get a bridge"), the person using it wouldn't be doing engineering, no.

How come it is not engineering? Engineering is all about solving problems. Good engineers solve problems with less work and time and achieve same or better results (high efficiency).

I agree. Good engineering is about efficient outcomes.

The 10x meme is a software thing. From my experience as an engineer outside of software it is rare to be working on something by yourself mostly you are part of a team and you get the best results by leveraging the strengths of each engineer in the team.

To use the example in this thread Dan is the engineering manager, he assigns the latest project to Clyde. Clyde knows he is going to require some modelling work and that Alice is the CFD expert so he asks her to model some cases for him. He recalls that Bob worked on a similar problem for a different client a few years ago so he wanders over to Bob's desk to chat with him about what worked and what didn't. During the conversation Bob mentions he read a recent paper that might be relevant...

Clyde doesn't need to be 10x as efficient as Alice or Bob because he knows they can get more done by cooperating then by competing. That is efficiency in action.

Engineering is about solving problems, but not all problem solving is engineering.

The CMS example fits in with what the article is about, and really, what 99% of us will see on a day to day basis.

It is true that's what 99% of us will see/do. But that doesn't change a basic fact about good engineer - being able to solve "yet unknown/unsolved class of problems" and not just be able to solve "JUST yet unsolved problems". Plumbing is generally about solving "JUST yet unsolved problems" whereas engineering is about the former. Yes, good engineers will also be (will have to be) good plumbers and that's where the 10x thing comes into play in a big way.