为何不呢？让我将这些颜色遍及我的空间吧。

Why not? Let's have these colors all around the space.

youdao

你为何不在夏天来英格兰呢？

Why don't you come over to England in the summer?

《牛津词典》

你需要的是换个环境。为何不乘游轮去旅行呢？

What you need is a change of scene. Why not go on a cruise?

《柯林斯英汉双解大词典》

He said, "I had a lot of trouble, I took it to department stores and I said, why don't you sell this?

他说，当时我遇到了很多麻烦，我把它拿到百货公司，我说，你们为何不销售这个呢？

耶鲁公开课 - 金融市场课程节选

so I figured why not just keep going with it?

所以我想为何不继续沿着这条路走下去呢？

为什么是会计学呢？ - SpeakingMax英语口语达人

Why should we weigh all preferences that people have without assessing whether they're good preferences or bad preferences?

为何该同等看待所有偏好,而不区分其好坏呢？

耶鲁公开课 - 公正课程节选