Those companies that have secrecy as a cultural value are going to be at a clear disadvantage from a UX point of view. The web is getting faster. People in general are becoming less and less tolerant of load times and other delays. The success of native apps proves this. Choosing secrecy will hurt your company unless you truly have a sauce so special that people will be tolerant of latency to taste it.
Native apps are the last refuge of companies that want to maintain end-to-end secrecy throughout the entire stack. The fragmentation of smart phones suggests that web apps are the future because every apps with social features is less useful if only people with the same kind of device as you can use it. Companies will have no choice but to develop in a space that is open.
As a consolation to companies with secrecy as a cultural value, the locus of computation is increasingly blurred between the browser and the server. The source code of most advanced client-side javascript apps that I've seen so far look like swiss cheese in that they're all full of holes, where the holes are functionality that is handled server side and are often the most complex tasks that an app is performing for the user.