It's not a joke, though there is more to the story.
Sports is an expensive venture, especially trying to change the sporting habits of people and their support. When the organization is relatively new, the folding of a professional league is a fate that is never far away. Consider that NFL Europe, through its various incarnations, is actually older than MLS.
That didn't save the league, however.
For all those who disparage MLS, and granted, there are many, many deficiencies - it's hard to encapsulate how much the league has assisted young Americans and their development and visibility in the game.
Yet I've never been of the mind that fans should support MLS out of some obligation. Go to games because you love the sport and the team. If you don't feel that way, don't go. No one can be entertained while doing something out of guilt.