I have used Btrfs in production and I would say it's great. It's super easy to just add an extra EBS volume and attach to a Btrfs volume and now you have more disk space. Performance is good enough for me as well, I used it as storage for InfluxDB and Docker.
How much did you deal with snapshots? Because I've had crippling performance problems stemming from them. Even something as simple as having 90 daily snapshots and deleting the oldest few can cause trouble, where the filesystem does not respond to any requests for multiple seconds. And that's on an SSD. I don't remember if it was deleting snapshots or running balance, but I've had Btrfs on a hard drive not respond to I/O requests for two minutes. A light-use server that had snapper running for a few months fragmented so badly that it regularly hitched up even after snapshots were paused. I had to migrate the entire filesystem.
I'm still using Btrfs on my backup system, but that's only because I like the dedup enough to overlook the brief hangs.
Unfortunately, RedHat tends to be the trendsetter in the Linux world. Once it's gone from RHEL, it'll be gone from most other RPM based distros soon enough. It's kind of a shame that one company has grown to dominate the Linux software ecosystem, often to the detriment of all involved.
On the contrary, RHEL ships a relatively small subset of packages, and is especially stingy on kernel features in order to make the distribution supportable.
Btrfs is definitely not gone from Fedora, for example.
(Disclaimer: I'm on the virtualization team at Red Hat).
I don't think that number is even close to accurate. SLE almost certainly makes up more than 15% of the market alone. And that's ignoring all of the other enterprise distributions.
I believe that 2015 estimates from the IDC[1] had RHEL at ~60%, SLE at ~20%, Oracle Linux at ~12% and "Other" at ~8%. But I can't access the document at the moment.
Number of installations is not also necessarily a good metric. Red Hat is a very large company with a lot of money and and a lot of employees working on upstream Linux projects and driving their direction.
There are not that many companies doing the same. Which is why they have a lot of influence over the direction of things.
Luckily this is only Redhat, not Btrfs itself.