Knowledge source:- I run an app dev agency creating apps for statups since 2010, have been principal supervisor to more than 100 app projects so may know a thing or two about technology and app market.
Go for native (even if one platform):-
1. If your App is a fresh new product (unlike an extension of existing popular website on mobile) and getting early adopters (your future evangelists) is important than any other thing.
2. If you care about first impression on users in terms of app's performance, speed, competitive UI.
3. If you know that getting popular one 1 platform only at first is enough to go further in the market with new high quality versions, for ex. Instagram was iOS only, so as whatsapp didn't launch on all platforms on day 1, even the clarity App is on iOS only for now.
4. If you believe that instead of targeting many platforms with an inferior product, it is better to target one at a step with a superior native app.
5. If your app is no banking app that has many security layers compelling it to go via web route.
6. If you know even facebook tried hybrid and cross platform for long and then finally switched on native ones because of the inferior user experience of latter which was causing them revenue loss from advertisements.
7. If you want your app to be well optimized in terms of memory and resource consumption, should take best advantage of native features and capabilities.
8. And if you know that "creating an hybrid app and creating a "good quality comparable" hybrid app" are two different efforts and the latter one would ultimately "COST" you as good as you'd pay for "Two native apps" development; while the former is mostly "nice to have".
9. If you know that your end user is not bothered about how many source codes are you maintaining and how you update each app at all, and all they look for is a superior experience which an hybrid app can never offer.
Go for hybrid or cross-platform:-
1. If your product is already popular on other platforms like web or Android (or iOS) and you just want to extend its reach by launching another platform tweaking the web technologies.
2. If you really believe "doing it quick" is more important than "doing it right".
3. If you want to bypass native controlled environment for any additional benefit (can elaborate more later).
4. If you have no easy access or budget to hire native developer (though hybrid web experts also charge same on equal experience).
5. If you know web technologies yourself and having to incur no development cost (even in that case I'd suggest you to utilize your web skills in creating the backend and web front end (responsive) of your system but as soon as you need an app then go native.
Bottom line; a Native App is more "focused" towards its end user while an hybrid one is mostly a decision influenced by creator's own dynamics and choices and priorities.
Feel free to agree, disagree, enhance or condemn my answer; I'm only a leaner and won't mind changing thoughts if given good reasons.