Is it ok to steal ideas from YouTube?

The most withering judgement one creative can pass on another's work is; 'it's been done'. In our peculiar segment of our peculiar industry, originality is valued above all else, even intelligibility and efficacy. The current head on the chopping block (or chopping blog in the case of Campaign Brief) is JWT's new spot for Allen's lollies. In it, a giant doll walks down a city street, blowing bubbles that turn into sweets.




Now regardless of any other considerations, it does bear remarkable similarity to this piece of film posted by a company called The Electric Pig.



Or even this viral campaign for Levi's Jeans by BBH in London.




Predictably, the creative community cries 'plagiarism'. And it's hard to believe that at least some of the people involved in the Allen's job weren't aware of the Electric Pig project.
But does it matter that creatives find inspriration on YouTube? In Oasis' pomp, Noel Gallagher proudly noted that he stole most of his ideas from the Beatles. The Rolling Stones started out overtly and publicly trying to mimic Southern Blues artists like Muddy Waters. Visual artists and novelists are also proud to identify the origins of their ideas.
Perhaps these other creative types understand that there is little that's absolutely original in the world, and instead try to move the good ideas that exist just one step further. Or mix two existing ideas together to produce something new.
However, unlike pure artists whose work needs to stand in it's own right, we are commercial artists who use ideas to promote and sell our client's products.
Is it right to hold ourselves to a higher level of creative accountability? Is the 'it's been done' argument a reach for higher standards or nothing more than self-indulgent creative naval-gazing? Should we be less concerned about where an idea comes from, and put more thought into making sure it achieves what marketing objectives it is meant to?
There are 20 hours of content uploaded to YouTube every minute, let alone other video sharing sites like Vimeo. If we discount all of this, what are we left with?