There are generally 2 very different kinds of carpenters in the world: framers and finish carpenters. One is not better than the other, but they are very different. Framers provide the skeleton for the house - so they feel their work is very important. Trim carpenters know that the quality of their work will register as the quality of the building - so they feel their work is very important. It is extremely rare to find a single person (let alone an whole company) that enjoys both and does both well. (Bob Berg is the only outlier I can think of right now.)
Concrete is similar: there are people that place concrete (commercial constructors call this "div.3") and they are important. There are people that overlay, stain, polish and coat concrete (commercial constructors call this "div.9") and they are important. Very rare is the person that enjoys and does both well. (Troy Lemon is the only outlier I can think of right now.)
The other metaphor:
Professional football started in 1890s in the US. It took 50 or 60 years before the players were anything other than completely interchangeable. That is, up until the 1940s or 1950s they were all pretty well-rounded athletes that played just about any position as well as the other. 60-70 years later, there are very clear physical characteristics of each position.There are 22 men on the field for any given play now, and it seems unlike that an "All-Pro" player of any one position could start in even 4 of the other positions. Most could not start in more than 1 other position.
To build a house, you need many different types of craftsmen. To win a football game, you need a myriad of different types of athletes. To install outstanding architectural concrete, you need 2 separate teams. What makes us great at creating detailed patterns makes us bad at getting the concrete truck poured out quickly enough. What makes a person great at placing very flat concrete floors will make them bad at staining concrete. Sure, good craftsmen can learn anything. Someone really playing to their strengths can't be beat though.
I can say all this humbly having started a "placement division" only to shut it down 18 months later. From our countertop work, we knew more about mix design, reinforcement, consolidation, and curing than any 3 placement contractors in our market put together. We were terrible at it though. We were just not playing to our strengths. Cabinet makers may know more about wood than framers, but that doesn't mean they should start framing.
We have seen dozens (maybe hundreds by now) of floors butchered by "the concrete guy". We can always fix it. Sometimes it is so much more work to grind off what they did and start over it doesn't make sense to do it. Given our passion, it actually hurts our hearts to see great clients back away from concrete flooring because of the wrong team starting it.