Where do you feel it is shoehorned in? Firestore is easy to access from App Engine and Cloud Functions (and GKE/GCE as well) using the built-in service accounts, it has managed export into BigQuery. Would love to know where you found friction when using it with other GCP services.
> Why is Google so bullish on this thing?
While I can't speak for Google as a whole, I'm personally bullish on Firestore for a few reasons:
1) Gives you the same "client-side only" model that Firebase popularized. This makes creating applications much faster as you remove the whole server side component and basically all your ops work.
2) True "serverless" pricing and ops. Because you only pay for reads/writes and not instance time, your costs scale linearly with your app's usage. And you don't have to worry about sharding or other operationally complicated things to scale your database as you grow. The caveat here is you have to structure your data and queries well, otherwise your costs will skyrocket [0].
3) Gives you the same "server side" functionality as Cloud Datastore (which Firestore is basically the next generation of [1]). This means you can use Firestore in place of a traditional NoSQL database like MongoDB.
4) Strong consistency. One of the biggest problem with Cloud Datastore (and most NoSQL databases) is eventual consistency. Datastore worked around this with "Entity Groups" which in my opinion were super clunky to work with and very limiting. Firestory is strongly consistent so you don't have to worry about this even at scale, which is super nice.
5) GCF Triggers. The fact that you can trigger a cloud function when something is written to the database is very powerful, it's basically like a traditional database trigger or stored procedure but you can do anything.
The biggest feature gap for Firestore is the querying abilities. While it is way better than the original Firebase DB, it's nowhere close to a relational database or something like Cloud Spanner. The team is working on it though.
The "real time" stuff is interesting but not really super relevant to the things I like to build.
[0] https://hackernoon.com/how-we-spent-30k-usd-in-firebase-in-l... [1] https://cloud.google.com/datastore/docs/upgrade-to-firestore