I think there is a design issue in https://github.com/symfony/symfony/blob/master/src/Symfony/Component/Console/Helper/DescriptorHelper.php#L68-L70

It will be more fexible if the descriptor will access the output because

• Less memory used
• The descriptor haven't to deal with \n
• The ouput is not blocked
• And Descriptor will be able to use another help.

But I think it will break the BC :(