I agree with you. There is something about Salesforce in particular I feel people don't trust to be a good steward of acquired products.
I don't feel it's deserved even though I worked for an acquired company that certainly did fail because of their leadership—I think we were the exception though. For Mulesoft, Tableau, Quip: I don't think it's clear these would be successful companies on their own.
They paid a ton of money for Slack and need to protect that investment.
Is there a clear example of Salesforce failing at an acquisition? Or do people see the examples I gave above differently than I do?