I apologize if this question sounded rude to you. But, you could have cor-related it with other commands as well which we may not understand and we have to follow them. Ever thought about ‘ghusl’ after ‘ejaculation’? you can still be ‘clean’ if you just washed your genitals, right? but why Allah asked us to take shower/bath? without ‘ghusl’ you cannot do so many things. While ‘ejaculation’ is also a natural thing which may occur for any reason, ever complained about that ? (if you are female then you got different reasons for ‘ghusl’)
http://www3.pak.org/gupshup/smilies/smile.gif
We oughta be Changez like, don’t we?