The sheer amount of rewriting that is being done every day around the world because people didn't bother understanding what they were doing (and how they should have thought more before trying to make it work) disagrees with this.
>it's not very useful for the every day programmers out there
So, programmer's talent is not being used to their fullest. The ones which can't understand basic theory can be easily condemned to always be mere users of tools while never improving them. They run a greater risk of becoming obsolete or devalued.