I'm intrigued.
We encourage cabin crew to speak up if they are concerned.
We equally welcome passengers speaking up, if they too are concerned, or even happen to notice something amiss.
After all, once it's been looked at (whatever the issue) fears or concerns can be put to rest with a rational explanation.
There have been a few reports where the Cabin Crew, and on an occasion the pax, were praised for doing just this.
And yet, here we have a trained professional pilot being criticised for speaking up.
Granted, the wording or tone may have been less than appropriate. But it is the intent and the message that is important, not the delivery. In this more educated/informed world, we should be able to put aside any personal irritations and look at the message for what it is.
As for the de-icing itself.
Surely it was the responsibility of the crew on board to take all practical steps to ensure the safety. I say practical and ensure deliberately. In this instance to de-ice I would have thought is obvious. It helps to ensure that if anything else happens, airframe icing will not be a degrading factor. As for the practical. The forecast was for snow. The airport is going to be resonably well prepared. Tower even expected it. An on time departure into the sea is a lot less appealing than a 20 minute delay.
As Dani pointed out, getting away with it this time does not make it acceptable. Suggestions that this was the right call this time, is based on the hindsight situation that nothing else happened. We don't plan for nothing to happen, we plan to ensure that if something does happen, it won't kill us.
If we don't consider these things important, then why bother with a Wet V1?
The cabin crew announcements often state that their primary purpose is the pax safety. It is also the flightcrew's. (sorry to state the obvious) Once passengers are onboard, all normal steps should be taken to ensure their safety (as well as our own). The company schedule and the profit on that trip should be secondary.
It smacks of press-on-itis. Something that we are constantly reminded to be wary of.
I can understand the view that it isn't the place of ATC to make the call. It is the flightcrew and a/c commander. It is expected that he/she will do so as part of their remit.
I can't see that it was the right decision, despite the fact that nothing happened.