[c_shu]

The same goes for many other icons. Like rss, wifi, and shutdown icon.

It makes sense, because once an icon becomes popular reinventing it with another design makes people confused.

[fbnlsr]

Isn't it different because the RSS, Wi-Fi and Shutdown icon have been designed to represent a protocol and/or system?

The iCloud "cloud" icon was designed to represent a product, which implies other products could/should have found something else.

[fjsolwmv]

Apple didn't invent the cloud.

Apple's iCloud icon is a cloud icon. Apple's branding strategy is to hijack and monopolize common words like "apple", a warbof conquest against the English language