It is normal, expected, and healthy to offer criticism of self interested proposals. And mock even. What is unhealthy is to imply someone said what they did not.
If that's what this is, a bank-shot snarky criticism of the proposal, fair enough. I read it instead as a criticism of a stakeholder having the temerity to make a proposal in the first place. It's not their job to anticipate and capture all your objections. That's your job!