Slogans are like gimmicks, they often don't have a lot of substance, but they sure are appealing. So are slogans unhelpful or helpful?
On one end, a good slogan is a good reminder. Useful. A good slogan supports the building of good habits. A slogan like "you are what you eat" can help remind someone to be careful. In education, a good slogan might be "observe carefully and ask questions".
On the other end, a good slogan is a great excuse. Unhelpful. And the unhelpfulness is usually attached to ex-post rationalization, justification. A slogan like "love conquers all" is tied to the mental pattern of all-or-nothing thinking. Using the slogan, our loved ones can be both cherished and dismissed. ("They just need to love them more, and they do, I have to wait" is consistent with the slogan. But so is "they don't love me enough. Let's find someone who does")
The unhelpfulness of a slogan is often proportional to its vagueness. Vagueness about who and what and why. The slogan to "Save America" or "Save Our Community" is used by people of all sides of politics. It is a slippery slogan, and can be morphed to support just about any view. SAVE AMERICA by protecting abortion rights. SAVE AMERICA by ending abortion rights. Same pattern with immigration, regulation, etc.
The opposite of vagueness is a clear prediction. If we do this we will get that. And then with a clear prediction or hypothesis, we can gather data and determine whether it is true or not. Or at least if it is true or not today, or in this case.
But in the calculus of slogans, vagueness is the superpower. Vagueness grants a slogan the ability to always be right. It connects to the drive of people to always be right. And what is better for someone who wants to always be right, than to have a slogan or belief that they cling to dearly, and that can never be proven wrong, and can always be twisted after the fact to be true.
Such things are not helpful for the development of the mind and the development of insight awareness and careful observation. But those things are not the priorities. For many people they just want to feel safe, and feeling safe means they want to feel right (for some people, not everyone). And it is much more important, much much more important to feel safe with a vague slogan, then to have something that can give us clear direction by being testable. Because testable hypotheses are dangerous when we want to be right. Or when the rewards of our life depend greatly on being right.
For myself, my path hasn't been to get rid of slogans. But it's to be very careful about when slogans are helpful and unhelpful. And I would say more than half but less than 75% of the slogans I have adopted over my life have been UNHELPFUL. And today, I do have many slogans, unsurprisingly they are mostly Buddhist slogans, and they are helpful for now. But if I ever start using them to justify being right, protecting myself from seeing and observing carefully, those slogans will turn unhelpful. And I need to always be on the lookout for that possibility.