1. Big reason: My Football Club didn't ask for money up front.
I was tempted to join MFC when they were asking for folks to say that at some point they'd pay $70 to be a part of the project. I eventually didn't, but I might eventually.
I don't think I'll ever pay the $50 MSC is asking, especially since they're asking for it up front, even before there is enough people to say they would join.
By not asking for money up front, but rather a show of support and an indication that you would eventually pay to join, MFC was creating a sense of urgency as we saw the number of members move upwards each week and created a sense that they weren't just out trying to steal your money.
2. MFC was a fan thing, not just a soccer/football thing. The folks behind MFC wanted to change sports ownership, it just so happened that the country they lived in (as most of the world) was a soccer/football country.
If this experiment happened in the United States first, I could see them doing it with an independent baseball team (United League, Golden League) before a soccer team. I'm a big soccer fan, but I also live in a baseball country.
The folks behind MSC seem to have taken the idea too literally.
3. There is already a tradition of fan-owned teams in the UK.
MFC was revolutionary not because fans would own a team, but because the fans would be connected through the web in order to manage the team. Fan owned teams are a not uncommon, if not popular, model in Europe and especially in England.
Starting a fan owned soccer team would be a big deal in America and especially if it were a web-based effort. The fans of the California Victory tried to save their team by following a similar path as many other fan-owned teams in England, but they failed.
Jumping to a MFC effort in England was probably a much smaller jump than trying to make the entire leap in America.
4. General trust issues based on behavior
In addition to asking for the money up front, the behavior of the folks behind MSC has been shady. Example here.
I heard Trevor Hayward, one of the guys behind MSC, interviewed on MLS Talk a few months back, and I got the impression that Trevor didn't know what he was talking about.
5. General trust issues based on background
Will Brooks may not be famous, but he is a known quantity in football/soccer circles in England. A former journalist, he knew the lay of the land, and people knew him.
Who the hell are the guys behind MSC?
But, don't worry. If MSC isn't going to work out, there will eventually be other web based sporting team projects out there. I'm probably never going to join MFC, but the idea is too good to die.