Yes, I understand that it doesn't help expand the fanbase. People want to see people they can associate with and, for whatever reason, they don't associate with the Kenyans. If they heard the personal stories of these guys, they may think differently but they aren't going to bother. That said, I don't think you're going to lose existing fans with a 2011-like season. If anything, it's raised my interest and excitement for 2012 a bit.
Right, though that is anecdotal. I will confess, trying to parse out the Mutais seems rather tedious and I can see how it might seem even moreso to less interested and intent fans. Reavis is right, these guys display little personality to draw in followers. It is not that they look the same, really, it is that they appear essentially similar in the absence of known personality traits. Also, in this competitive sports market, if you are not gaining ground then realistically you are losing.
That was a single installation at a single event but imagine if they did a traveling exhibit. This kind of display in Chicago, New York, Boston, Houston, Duluth, Minneapolis, Sacramento, and elsewhere in conjunction with those cities' marathon weekends. No doubt the infrastructural issues you raise are real issues that need to be addressed if we want running to be more mainstream but promotional events like this sure wouldn't hurt.
Beyond infrastructural issues, it is part of a corporation's advertising campaign and as such will only go as far as it fits within their budget and serves their marketing aims. Again, with no overarching organizational structure to push a continuous marketing message we are left with a mixed bag of what these companies feel works right now. It is not a bad thing at all yet relying on corporations to 'spread the gospel' and promote the sport will always be a limited prospect. There needs to be more if there is to be significant progression. Else it will remain the same as it ever was.