To get something out of the way - yes, I do say no quite often. But even if "no" is in itself a complete sentence (true!), I still think it's a really boring sentence. Make better sentences.
If conversations are two-way streets, no is like a stop sign. There's no opportunity in no, no next steps, no learning, just an end to moving ideas around. No is for people who know it all.
I don't think this word has a place in groups that want to achieve a joint goal in the best way possible. No, I actually don't believe it has a place. And I can even explain why that is.
Great teams are places to share ideas, and to jointly find and give opportunities to improve. So if someone shares a shit idea with you, sure, go ahead and say no. But there's no teachable moment in shutting people up. There might be a moment of feeling smart – very ephemeral. Reality is that most folks don't come around presenting shit ideas, there's a deeper reason for that. And understanding that reasoning, understanding why and how people make decisions, their reasoning, that's a good point to speak about. But you will not if you shut people up, if you're a human-faced stop sign. So don't be.
What's better? The first thing is to assume positive intent. To be fair, up to a certain point - there's always douchebags. But assume that the overwhelming majority of people communicate with good intentions - intentions of being constructive, helpful or just sharing a great idea.
Since I'm usually assuming that the people I'm working with are neither dumb nor evil, what feels like a not awesome thought for me in the beginning might just be plain ignorance. So you go and ask until you truly understand not only what someone is sharing with you, but also the context around it. And that might be anything from individual experience (I built something like that before), environmental particularities (time pressure) or implicit assumptions that no one really knows about - unless it's shared. Active listening and putting in real effort to trace a thought that lead to an idea is what will actually make you smarter.
Chances are you'll still disagree with some things, and oppose others. That's fine, otherwise communication would serve no final purpose. But rejection can be opportunity, and this is why communication needs to be a two way street, not some boulevard of stop signs. There's an opportunity to explain your side of things, your reasons, motivations – your experience, environmental particularities or implicit assumptions. And even biases, if identified as such. But there's just such a striking difference between saying no – an unhelpful rejection and explaining opposition to an idea. There's learning in explanation, even if it's to understand someone else's opinion better.
Maybe no is not a boring word, maybe it's just super not helpful. No, don't use it.