Elaborating on nerzhin’s comment, which I think is well stated: the tradeoff between clarity and politeness is not absolute. If politeness is non-habitual and thus difficult, it requires a lot of your energy and attention, and you have to give up some of the energy you could otherwise have spent being clear. This is much less the case when you’re very practiced at speaking courteously, because that action becomes automatic; you can then use all your conscious focus on clarity.
It’s much the same as the speed/accuracy tradeoff in, say, typing, or playing a musical instrument. When you’re still learning how to do it, you have to type or play slowly if you want to make sure to get it right. Once you gain the muscle memory to do it right, you can speed up because it’s not so much work to be accurate any more.
Elaborating on nerzhin’s comment, which I think is well stated: the tradeoff between clarity and politeness is not absolute. If politeness is non-habitual and thus difficult, it requires a lot of your energy and attention, and you have to give up some of the energy you could otherwise have spent being clear. This is much less the case when you’re very practiced at speaking courteously, because that action becomes automatic; you can then use all your conscious focus on clarity.
It’s much the same as the speed/accuracy tradeoff in, say, typing, or playing a musical instrument. When you’re still learning how to do it, you have to type or play slowly if you want to make sure to get it right. Once you gain the muscle memory to do it right, you can speed up because it’s not so much work to be accurate any more.