I'd argue there's a lot wrong with reinventing the wheel. People don't seem to care about the inevitable waste of programmer time and effort that comes with introducing a new programming language or library, assuming it gains any traction.
There's little risk of that I think; even very strong and innovative languages struggle to gain traction. It doesn't tend to happen by accident.
And let's not forget that writing your own ORM, compiler, programming language, hardware driver, etc., (even blog engine!) is an amazing way to learn. But it is good to know whether a project is a hobby project to help learn, or a serious project aimed at getting traction, or what.
I don't know, C++ is pretty popular. ;)
Most programming projects start with the intention of the latter but usually end up becoming the former.
Linus Torvalds 1991
Most projects start out as a hobby / experiment and a tiny fraction of those become popular.