The comparison to Linux Desktop is correct but for the wrong reasons. Like with bitcoin, nobody has any reason to switch to a Linux Desktop since the existing solutions already do everything people want. If you're non-technical and are already comfortable with Windows or Mac, you gain nothing by switching to a linux desktop.
Having one single, well-branded app is easier to use than 87 random no-name apps.
But there's no need for this to be a cryptocurrency app, that's the point.
These amazing things that cryptocurrency enthusiasts tell us could be made possible using their magic beans - millions of people are already doing them just fine.
Acquiring bitcoin will become incredibly simple with services like azte.co, which work in pretty much the same way that most people used to top up their pay-to-go phone less than 20 years ago. People forget how rapidly things move.
If you think at the level of "this is how it works now", you will never comprehend the potential of Bitcoin. The exchanges which operate in the bitcoin space now will be about as relevant as phone booths were as a means of making phone calls remotely. People will forget they ever existed.
The way most people will acquire Bitcoin in future is the way they currently acquire fiat money - in exchange for their time and labor. There won't be any other "exchange" process.
People don't use Bitcoin because it's complicated and unstable. It's complicated and unstable because the types of people that use it want to speculate with it or use it for illegal purposes. Just making it more approachable won't fix the stability issues, so it likely won't increase the number of users in a meaningful enough way to get it to take off.
The same is true for desktop Linux. And installing Linux is often easier than installing another OS (Windows or macOS). Take Ubuntu or Mint, for example. They're the most popular among users new to Linux, and installation is as easy or easier than Windows since drivers come preinstalled and the user is prompted if proprietary drivers are available. The problems arise when trying to use software not deigned for Linux (e.g. MS Office), and this is getting better all the time with investment into the Windows compatibility layer by Valve.
However, the chicken and egg problem will always be there. A decentralized system like Bitcoin can't really be saved by investment from a third party since it can't solve the volatility problem without centralization.
For this reason, I think looking at centralized, but not government run, systems is interesting. For example, GNU Taler is a centralized cryptocurrency that can be used for anything (one example was currency used at conferences) with incredibly low transaction costs. I think it's interesting because it gets people used to using something digital (and not government provided/managed) to make transactions, but without having to deal with volatility inherent in cryptocurrencies, and once cryptocurrencies stabilize, perhaps they can be a drop-in replacement.
I really want decentralized currencies to work out (largely to make traveling less of a pain), but nothing I've seen is worth making more user-friendly.