Why does passing wind (gas) invalidate the wudu? If it becomes necessary to take wudu after passing wind (gas) then, isn't it a waste of time and water?

Why does passing wind (gas) invalidate the wudu? If it becomes necessary to take wudu after passing wind (gas) then, isn't it a waste of time and water? Is it necessary to wash that part? and Are the things that invalidate wudu mentioned in the Quran?

Dear Brother / Sister,

1. Our Prophet said, “A person must make wudu (ablution) if he hears a sound or perceives a smell of passing wind (gas).” (Muslim, Hayd 26; Nasai, Taharah: 115) in a hadith, stating that passing wind invalidates wudu.
Water and time spent for worshipping is not waste; it is worship. If there is no water or if it is only enough for obligatory requirements, one can make tayammum. 
Wudu becomes invalidated when someone passes wind but it is not necessary to wash that part if no stool comes out.
2. The fard parts of wudu are mentioned in the Quran but the things that invalidate wudu are not mentioned. Our Prophet explained the things that invalidated wudu and mujtahid imams reached some conclusions based on those hadiths.

Please click on the links given below;

Wudu’ (Ablution)

How is wudu (ablution) performed?

Questions on Islam