Why does Google keyboard not give suggestions for some apps?

[AC Question]

I have a nexus 6 with fresh install of MM. I like to google keyboard but it doesn't provide suggestions in all apps. The google search app for one. It also doesn't for certain forms that require my email address etc. I have all settings turned to 'on' and a quick test with Swiftkey shows that to work correctly. Do I have a problem or is this just the way it is?