As one of the commenters there points out, you can just do this with ssh. Which means you're ssh'ing to a machine you probably control, which means you would have had to install the stuff you want at some point on that machine anyway. Why not just do all your development from that machine (or, if you don't want to, why not just install the package on your local machine?).
I think the authors idea is that you would ssh to a machine that someone else controls and is providing access to. E.G. For a dollar a month I'll give you shell access to a machine where I've set up ImageMagick, and I'll give you a set of scripts that make running ImageMagic commands on your machine transparently run them on mine instead.
Yes, the value here is in 'where I've set up ImageMagick'.
If I have a task that could be made easier by having ImageMagick, but I don't have it on any machine I have easy access to, then I have to deal with the overhead of getting the package, installing the package, configuring the package, and possibly removing the package when I'm done.
Even though I know how to do all things, it would take me some time to get it all done, and then I'd have to waste brainpower in those things, and not the real problem I'm trying to solve.
A lot of that is solved by the "better" distributions, e.g. Debian has nearly everything under the sun.
But not everything. That's where the opportunity might be.
I probably wouldn't pay a dollar a month just for ImageMagick, but I might pay a few for shell access to a machine that has all of the new and shiny things available, things too new to get into the main repositories, and keeps them up-to-date and keeps adding new stuff, so I don't have to handle the sysadmin tasks for yet-another-box.
Sounds like a webservice with a REST API. Every non-Windows computer comes with a client out of the box.
In fact, for some of these things, I think I've seen REST APIs in existence, for the text and image conversion ones. The imagined "ru" command could just be a function or alias to curl/wget.
As one of the commenters there points out, you can just do this with ssh. Which means you're ssh'ing to a machine you probably control, which means you would have had to install the stuff you want at some point on that machine anyway. Why not just do all your development from that machine (or, if you don't want to, why not just install the package on your local machine?).