Guts? How about common sense. Hey guys lets put out a console with only mediocre games that way everyone who isn't a die hard nintendo fan can hear about how bad all of our games are and probably confuse that with the system itself somewhere along the way so that they never buy it! Great idea.
Really though all the hate just comes from kids who grew up on Nintendo and then realized one day that Xbox/PS/PC fit their new gaming tastes and interests as they grew up. Rather than seeing that though they just assumed that Nintendo sucks now meanwhile Nintendo keeps doing what they do and creating games that a younger audience and responsible parents enjoy.