You might be on to something but their product philosophy just seems to be.. different. Compare TeamCity to Bamboo; it's in a different league. Maybe that does come down to the extra human resources they can throw at stuff.
Their products are/were ambitious in an MVP environment.
Some TeamCity details are a bit odd, for example you are not allowed to run a development server and a production server with one license. Instead you should get an evaluation license, that is only valid two months at a time.
Conditional build steps have been requested by users for years and even though it's the most requested feature, nothing has happened for years.
Like Jenkins, Bamboo, TFS, VSTeam, TravisCI, CircleCI, GitLabCI, UrbanCode?
Maybe it's just me, but the CI/CD space is pretty crowded these days, and Jenkins is still #1 for a reason.
I don't find myself fighting TeamCity as much these days but there's alot if things I wish it could do better.
In fairness I have only tried Jenkins, CruiseControl and Azure DevOps.
What sets TeamCity apart is the use of Kotlin. You do have to invest a fair amount of time to get the most of it, but when you do the return is great.
Putting together a pipeline in Azure DevOps with tons of YAML is not a great experience.
As far as Jenkins is concerned I think that it's biggest selling point is that it's free.
Their products are/were ambitious in an MVP environment.