For example. If a subject (let's call him W) considers it important that there is no aggressive language, he will focus on this first. But for the second subject (let's call him L), the semantic content is the most important thing. And so, W and L communicate. And if W ignores the semantic content that L is trying to convey, again and again, no matter how politely W expresses himself, L will still feel that W does not consider him a person (does not respect him). And even if W has not received aggressive language from L for some time before this, he will soon receive it, and he may even think that the problem is only with L, because W did everything "correctly" (politely). This is also true in reverse (only not about meanings, but about "being polite").
The same applies here - a polite tone only guarantees that the person you are talking to will listen to your proposal and give a polite answer. Whether it will be accepted depends on what you are proposing.