Play Vault's Jonathan:
"I attempt to explain why downloadable first person shooter games do not achieve the levels of success they intend to do so and why they are often released to mixed or negative reviews. There are exceptions to the rule but the downloadable first person shooter genre is blown wide open and the pieces analysed."
BF1943 is good, but has very little content. If there was like 2x as much of everything then it would have done way better.
Section 8 is pretty good too, but just generally falls short in mechanics and overall fun.
Blacklight just isn't as good as those, but I wouldn't call it bad either.