>If React 15 was good enough for you when you started using it, it doesn't necessarily fundamentally stop working when React 16 ships.
No, but your project is seldom 100% finished either. So as you do minor changes to it, and want to use some new lib, you find out that it's not compatible with your old version.
And libraries stop get maintained too -- and when you finally try to make the conversion it will be harder the longer you have waited, because aside from porting your code to all new React stuff, you'll also need to find replacement for all those libs at once (not piecemeal, which would be the case if you kept the project up to date faster).
This could also happen for all kinds of external reasons too -- e.g. you use a third party service and they change their API. Or you update your OS and your old libs suddenly stops working. Or a browser deprecates some feature (like Object.observe that Google warns that it will be removed on March).
No, but your project is seldom 100% finished either. So as you do minor changes to it, and want to use some new lib, you find out that it's not compatible with your old version.
And libraries stop get maintained too -- and when you finally try to make the conversion it will be harder the longer you have waited, because aside from porting your code to all new React stuff, you'll also need to find replacement for all those libs at once (not piecemeal, which would be the case if you kept the project up to date faster).
This could also happen for all kinds of external reasons too -- e.g. you use a third party service and they change their API. Or you update your OS and your old libs suddenly stops working. Or a browser deprecates some feature (like Object.observe that Google warns that it will be removed on March).