Maybe I'm missing the point of this article? Writing a simple compiler is not difficult. It's not something for beginners, but towards the end of a serious CS degree program it is absolutely do-able. Parsing, transforming into some lower-level representation, even optimizations - it's all fun really not that difficult. I still have my copy of the "Dragon Book", which is where I originally learned about this stuff.

In fact, inventing new programming languages and writing compilers for them used to be so much of a trend that people created YACC (Yet Another Compiler Compiler) to make it easier.