Tiger:
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Snow Leopard and Lion:
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The progression to simpler, less pronounced shading appears to be obvious over the versions. Lion also removes the rounded corners, although the shading is quite similar to SL. Continue the trend and you will get the Yosemite look.
I have never experienced the desire to lick my computer display, that would be fairly disgusting. I do clearly see the 'wet' theme in Yosemite's UI.
As to the rest of your post, it seems to be rather emotional train of though gibberish, I can't constructively comment on that. If you want me to respond, please come up with some reasoning and not a steam of subjective epithets. I get that you don't like the 'flat' (I hate that term btw) design which seems to the the fashion at the moment. I hardly see how your personal aesthetic preferences are valid criteria to judge OS design. If you want to criticise some work, criticise it in regards to what it is and its intention, not what you like. Otherwise there is not much purpose in having a discussion.