The audience who are likely to make the most use out of a tool like this are not the same as the audience who would be comfortable using a command line tool.

I mean, you can replicate the core functionality of this fairly easily using awk, and if you're happy doing a bit of piping to perl or whatever, the fancier time re-formatting stuff is also easy.

In essence, the complexity in this tool (and what makes it cool) is the figuring out what you are trying to do without telling it - if you can run a command line tool you can tokenise the input yourself and you're most of the way there already.