Ask HN: What do you think about Salesforce's acquisitions?

Pretty much the title. I occasionally forget that both Heroku and Slack are owned by Salesforce. Is there any particular reason why Salesforce does not try and integrate them closer into their platform/brand identity? Other acquistions that come to mind are Google acquiring products like YouTube, integrating it with Google+ login back in the day, Microsoft with Skype, Facebook with Oculus/WhatsApp/Instagram. Any reason why Salesforce treats its acquisitions "differently"?