If I have a desktop app which talks to Redis (for whatever reason), what this means is that I can't realistically produce a version which works offline. Depending on the market, that could be huge.
Instead of running "redis.exe" (which you installed), you run "virtualbox redis.vdx". You could even have the inner redis use the outer disk with a little more work, running the internal vm read only. Configuration is slightly more complicated, as you have to both configure the inside redis and the outside virtualbox -- but it's all just a few short text files, and you only need to do that once.
You can produce a version that works offline. You can even bundle it inside your product (virtualbox and redis both being free). And you can do it today without antirez's help. Really!
EDIT: online -> offline; typo.
On the contrary, porting front end software between platforms makes a lot of sense, but that's a completely different story.