I wouldn't exactly call it proprietary sabotage. The same type of thing is true for graphics applications. Or, even office applications, for that matter.

For example, Photoshop files can't be opened by most other graphics programs in their native format, but you CAN export to a more generic format (TIF, TGA, etc) for use in other graphics apps. However, the layer effects don't usually translate well. It's the nature of graphics applications as a whole.

Same is true of office type apps. Word files can't be opened in many other office software suites, but you can export the Word doc to RTF format and it can be opened in another app.