I think others have already done a good job of describing how programs like that help make you a better programmer, and can be inspiring.
I'd like to add that something that I find interesting and inspiring about programming is managing complexity. That's something that's not as easily explored with programs like the above. But for example, you could try to create as much of a spreadsheet program as possible in a few hours. Do that 4 times starting from scratch. How can you organise the code in such a way to make it easy to read, performant, maintainable, and fast to write? What language features will you take advantage of? Maybe try making a part of a word processor, an IDE, a raytracer, an HTML viewer, an FTS engine, a relational database, etc. Try implementing mvc, or reactive, or two way binding UIs. I would consider these sort of a different genre of poem, that let you explore a different problem space. Maybe this might be the genre that you're more interested in?
I'd like to add that something that I find interesting and inspiring about programming is managing complexity. That's something that's not as easily explored with programs like the above. But for example, you could try to create as much of a spreadsheet program as possible in a few hours. Do that 4 times starting from scratch. How can you organise the code in such a way to make it easy to read, performant, maintainable, and fast to write? What language features will you take advantage of? Maybe try making a part of a word processor, an IDE, a raytracer, an HTML viewer, an FTS engine, a relational database, etc. Try implementing mvc, or reactive, or two way binding UIs. I would consider these sort of a different genre of poem, that let you explore a different problem space. Maybe this might be the genre that you're more interested in?