> I just refuse to label this behavior as being constructive, desirable, something to cultivate and protect.

> I see this "complainy" way of engaging as unproductive

You are merely defining "constructive" and "productive" to whatever suits you.

> I get wanting to vent and wanting to be heard but solutions should come first.

One thing I learned after learning all these skills (later in life), is to openly tell others "The word 'should' is not in my vocabulary."

should is usually a means to be lazy in explaining your thought process. Why should solutions come first? What problem are you trying to solve, and why that problem? Understand that addressing emotions is solving a problem - it's just a different one from what you're trying to address. Solving that problem (well) often results in fewer problems down the road. The one you're trying to solve likely won't.

To directly address the topic - solving the emotional problem first makes them more open to listening to your (other) solution.[1]

> but I also nudge, coach and hope they develop healthier and more constructive ways of dealing with their problems.

Tip for the future: Being judgmental is going to negate most of your efforts. There's nothing wrong with nudging people down a path you feel is right. There is a problem in labeling the behavior as "unconstructive".

And, as I said in another comment, I'd wager good money that your behavior is not particularly different. You may not do it as often as the people you speak of, but you do do it - and you won't recognize it until you dig deeper into understanding the bigger picture. Once you do (as I did), you'll find plenty of examples in your life - past and present - where you behaved in the same "unconstructive" way, and didn't realize it.

(And in the off chance you have realized it, and criticize yourself for those past trespasses, you are putting a barrier to improvement).

[1] And yes, that's true even for you! You merely have to go back to your life where someone told you something (that you later found to be correct) and you didn't follow it, and ask why. There are multiple reasons people don't, but this is one of them. Distrust, dislike, disdain, etc lead to devaluing things others say.