Thank you for saying this. Sorry, but you don't need a rocket scientist to build your glorified CMS, no matter how neat and innovative you think it is. When you're building the fault-tolerant, highly optimized code to align a communications satellite with a ground station, or sharding code to handle a database dozens of terabytes in size, then you can make a case that you need the top 1%.
For the 99% of CRUD sites, mobile apps, and glorified accounting systems that most programmers will spend their careers on? Not so much.
Actually, building a CMS is pretty difficult and I'd say you want to only use CMSs written by about the top 10%. Not quite rocket science but they're actually very, very difficult. There's a lot of tradeoffs to be carefully made, increasing exponentially as the framework tries to do more (with a lowish exponential factor, but exponential nonetheless) and a lot of ways to make simple things difficult and difficult things impossible. There is no pain like trying to use a CMS written by a bottom-25%er.
Using an already-good CMS to build your site is trivial and you don't need a rocket scientist for that. Depending on your needs you may not even need to be a programmer per se.
For the 99% of CRUD sites, mobile apps, and glorified accounting systems that most programmers will spend their careers on? Not so much.