Engaging in philosophy only alone (or only with like minded, agreeable people who will circle the wagons if someone dares to take things actually seriously) is a tragic waste of immense power. No wonder it gets so little respect, or attention.
Philosophy can be applied, but it takes brass balls.
Change is not always for the better. Vladimar Putin is changing the world, but expect that few here see it as a good thing. Putin, himself, is known to see Soviet Russia as good; the USSR also changed the world, but it is hard for many to see that as good, particularly the millions killed by the rulers. The USSR was a product of Marxist thought, and thus far no implementation of Marxism has been anything but highly destructive. (Regarding China, it's success came when they embraced aspects of capitalism and technocratic governance. Xi is turning back towards Marxism and China appears to be going backwards.)
Other philosophy would consider Marx as incorrect. For Plato, the point of philosophy is to find the Good, the Beautiful, and the True. For Buddhists (if I understand correctly), the point is to escape suffering. For Christians, the point is the mystical union with Christ. For these, effects on the world are a side-effect, not the point.
Personally, I think that the preoccupation with "changing the world" in the contemporary US is a search for personal meaning (via activism, or even merely "change"), since the ideas of modernity has erase all meaning from our existence.
Do you think it may be possible to use philosophy to change the world in a positive for most way (say, 80%+ of the global population), to a "substantial" degree (based on a global survey)?
As an analogy: consider perspectives (on whether flight may be possible) 100 years before and after flight was ~mastered (based on a global survey).
The problem is that we are talking about philosophy here and what is positive is being studied and discussed. And because we have not agreed yet, those changes would be more a power play then a right-idea (say positive) play. Marx is bad has been proved beyond doubt in practice. Still because it is all about power and change, it is a bad idea.
The question is that consensus is what is at stake in philosophy. Can all have one consensus. Can there be a truth ...
There is no ground rule in philosophy; you can have your professorship even but does you think you are right. I am not challenging as we hope there is something right out there even if it is contextual and individual and hence might not be universal that apply to all situation, all humans, ... And that the universe has no multi-dim and hence it cannot be self-contradict or self-refutated. Even if so, the issue is you are inserted there. How you do know you are the truth, the life and the way? God yourselves kind of? Why you impose your view on truth on me because you think that this is the truth? Why I have to believe in you.
Does truth/beauty/right is knowable (or is it thing-in-itelf?), talk possible (philosophy is a disease to be cured?), ...
Being Confuicus, Buddhist, Taoism, Muslim, ... or Hercaltus ... Of course you can be better than they are but have we agreed ...
Philosophy is IMHO first about raising questions. Obviously you provide answers. But it is the question and the process of finding the answer that is interesting or even truth to you. The result, ... it never satisified for everyone; sadly or happily.
To say there is a truth, a right, a beauty ... whilst we want to have one universal answer, but my answer might be different from yours and based on history of philosophy is that there is no answer. We might have to enjoy the journey.
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in practice, marxism is bad; Maoism is bad, Stain..... you still do not get it and that is a shock to me. Should we sing a song: How many people has to die because you believe in Marxism ... Back to line 1 I guess as we will never agree.
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When you do not think clearly and does not have an answer, and you just do it then it is just power grabbing and no doubt if you really have power, or even we do not have actually as time change whatever we do (but what is time?), we can believe our action can induce changes ... Hence, just power and change! And that is not about how right you are or how much truth you are. You just act and power-change as a result. As you do not think clearly and state clearly what this change might go to or even worst as Marx seems did not know or at least you do not think clearly or state outright what is his pathway to success. That is bad and that is how Marxism is wrong. Its development history shown you that. (Does Marx predict Soviet Union arise or even peasant China or more advance captialist stats will collapse instead?). Well, you still do not get it and to be consistent with my line, please go back to line 1 of course. :-)
Philosophy can be applied, but it takes brass balls.