Oh? You have a cross platform path separator builtin? Wow that must be totally worth 200 MB of garbage.
I'm sure the client will be fine with fucking around with the CLR / JVM all day instead of just downloading a 200 KB executable. It's just what they need, now not only do they need to update your application but they have a dependency nightmare too.
To be fair I haven't tried to release an app for Windows/OSX from Xamarin but my understanding is that it requires the .NET or Mono frameworks which on most computers is a 100 to 200 MB install.
For Java you're for sure going to have to download the JRE. When you start the app it eats gobs of memory.
Maybe it's changed but even Xamarin itself requires Mono to be installed, this is the kind of shit I'm talking about, you should download the app, drag it to applications, done. Or on Windows click Next a whole bunch of times.
Even the monstrosity that is XCode is a one drag install.
You mean someone else, which is the entire point of why you would use any platform/library/framework.