Your blog post blames a bug on Android fragmentation, but it sounds like it was your fault. You were not calling Environment.getExternalStorageDirectory(), which is the portable way of accessing the storage area where users saves file via USB mount.
I tend to find that with Android success is directly proportional to how much the platform is embraced as it is. Many people seem to approach it as a slightly different Linux, iOS or J2ME/J2SE and get very disappointed. If you fight it it will bite you in exactly that sort of way.
The problem is the API is huge, and the documentation isn't great either, so you're supposed to learn best practice from the apps in the OS source tree.
That API call is not sufficient. Some devices have more than one external storage device. For example some tablets have an internal storage point and the ability to have a USB key.
The function you are talking about only returns a single directory and my users want to use both if available.
It really isn't a big deal. Use reflection to find what works at runtime, and live with it. That's the price of the flexibility which makes the whole thing attractive in the first place.
The big problem is trying to cover all bases from the start: you won't. Attack it like an old school PC shareware dev, and respond to customer requests.
There are far larger problems with Android than this kind of thing. That things on external storage basically bypass the security model is a much bigger concern.
The brutal part is that generally customer requests are no better than "the bug is shitty app" or just "buggggggg". Thats where a responsive strategy sucks - reliable reports are few and far between.
