Why is (RPM) elasticsearch installed in /usr/share?

I noticed that both Kibana and Logstash, the RPM versions, install by default in /opt. This is correct, imo.
On the other hand, Elasticsearch installs by default in /usr/share. According to the FHS, this directory is for read-only architecture-independent data files.

Is there any particular reason for this? Will this change in the upcoming 5.0.0 release?

Best,
Dan

Update: updated the FHS link to a more current version of the standard.

Logstash will also be installing into /usr/share in 5.0.

Do you know why? Was this just to have Logstash aligned to Elasticsearch?

Yes. I believe all of the Elastic Stack will deploy to /usr/share in 5.0