Actually, as I understand it, this is a feature, not a bug. The idea of the MCC was to change the traditional "Don't just stand there: do something!" approach to disbursing aid. The MCC projects are large and very carefully designed, which is taking a lot of time. This may not turn out to make a difference. But the general approach of measuring aid by the amount of cash you managed to pump out, rather than the results generated thereby, was a very bad idea that the MCC was designed to challenge. It makes little sense to declare the project a failure on the ground that it's not spraying dollars over Africa like a firehose.
51 years ago, President John F. Kennedy made a very angry phone call.