directed at reader, a behaviour to unlearn 
"That will never work anyway."
Even if you're leftist, even if you're marginalized, there's a pretty good chance that you've picked up this habit of telling people that they won't succeed - it's uncomfortably widespread.
Think carefully: what are you hoping to achieve by saying this? If you just say that something won't succeed, you're not giving someone any actionable information on how to *make* it succeed.
Are you looking to discourage them? Because that's certainly what the practical effect of this will be - and you may be doing that without even thinking about it. You're actively making it come true.
If you're about to tell someone that something won't work anyway, regardless of whether you *believe* that it will - stop, take a step back, and hold that comment. It will not be a positive contribution, and there's no need for you to share that belief.
re: directed at reader, a behaviour to unlearn
It's hopefully not necessary to say this explicitly, but I will anyway: this of course does not apply to genuinely informing someone about a problem that needs to be considered.
But that's a very different kind of conversation, a collaborative one, and not a dismissive throwaway comment that gets thoughtlessly inserted into a post like "that will never work" usually is.
