It could work ... maybe
My past experiences with Mono were less than enjoyable and the results were far less than impressive ( it may be better now ) but the idea of cross-platform development does have its appeal for those who don't have skills in / on the targeted architecture.
AppForge's MobileVB ( before being bought then killed by Oracle ) was a plug-in which allowed MS VB6 users to write VB6 code which would run on a variety of PDA OS's. A bit slow at runtime but it was a breeze to use for anyone familiar with VB6 but not a clue about PDA OS's or the native tools. I would never have developed any applications for any PDA without it and the apps developed served their purpose. In that sense it could only be classed as excellent and I probably fit the intended target market here.
There have been previous cross-platform attempts, Java notably, Delphi/Kylix and REALbasic, probably others. Platform specific developers will no doubt see these as inferior to native development, but guess what - you're not the target market.
The biggest mistake anyone using such tools can make is to imagine that developing a cross-platform app is write-once, run on anything. For non-GUI code that's possibly so but there's a lot of tweaking needed to give every platform user what they expect in terms of look and feel. Java isn't a universal panacea there.
Some people won't like the idea, some will totally frown on the notion that MS VS users should even be writing code intended to run on Linux, but the way I see it is that if it brings apps to Linux which otherwise wouldn't exist it's got to be a good thing. Users want apps, only fanboi deveopers throw fits about how those apps are developed.