Today was a nice sunny day here and i was looking at the cloud while driving back from the beach (as opposed to the road). It made me think. Why do we find certain things beautiful and inspiring, and others ugly and undesirable?

Instinctual attraction to 'hot' mates is easily rationalized (I'll speak from male perspective now). We find fit women desirable because they are generally healthier, and thus more able to carry on your offspring. Men who are attracted to sexy women are more represented in global population because that particular trait is an evolutionary advantage. But what about things like clouds, and flowers, and sunsets?

Well, after thinking a while it seems it can be explained by exact same means.
We live on Earth, where there are plenty of clouds in the sky, and sunsets, and winds that shake the grass fields. These things generally represent natural environments a human most thrives in (favorable climate, with enough vegetation and precipitation (clouds). So just like with men who like hot women, those who like healthy climate are more represented.
Of course, nowadays we are generally isolated from nature (for all those who live in big gray industrial cities) but we still retain our natural bias to certain phenomenons.

Even from culture to culture here on Earth, standards of beauty vary.
Imagine if Mars was populated by some sentient life. Their perception of beauty would be completely different and alien to us, because Mars environment would favor totally different perceptions of beauty.