This is sad but not super surprising. Historically, if you had money and wanted a reasonable UI and cleaner integrations, you bought PGP (now from Symantec). GPG was always for people unwilling to pay. For the record I donated. I'm just pointing out that writing something that's bundled and distributed as part of something else means nobody thinks about your project, or in many cases even realizes they're using it.
I would like if someone with more understanding of the situation could outline the risks of allowing PGP to be the only implementation.