Lack of commitment (Score 3, Interesting)

I've worked with some open source projects, with disappointing results. A couple of reasons that we prefer commercial development:

Missed deadlines: The open source projects that we worked with had limited commitment to deadlines, and frequently missed them. When you're counting on product launches, this can be very painful

Lack of Support: Things never go wrong at 3PM. Instead, they always happen at 2AM on Sunday. Commercial outfits have dedicated people to help when this happens -- open source people aren't around.

Development of commercial features: Any commercial product has features or enhancements that aren't strictly bug fixes or new enhancements. These are unsexy jobs, but they need to get done. We found it difficult to get people to commit to them

Obviously, your mileage may vary. I'm sure there are some great stories about open-source, as well as even worse ones. But that's my $0.02.