If Mozilla succeed then there will be a common standard for all developers to code to, there will no longer be any worry about an app not working on Linux/MacOS

If Mozilla succeed then there will be a common standard for all developers to code to, there will no longer be any worry about an app not working on Linux/MacOS because the targeted environment is the browser. The browser becomes a VM, in fact it's already one but they want to make it far, far more powerful. This is a very good thing.