Even though I knew this was a satirical, silly book, I still expected to enjoy it. I grew up on the original Star Trek TV series, love his other books, and have enjoyed other fantasy/SF satirical authors, so I figured I was in the sweet spot for this. Nope, I am definitely not near the spot, much less the sweet part. Other reviewers go into depth about the plot and premise, so I'll just focus on how this book made me feel. To put this in another context, I love comedy movies of all types except slapstick/stupidity. This book is the latter, which means I think the agreeable audience (those who read fiction *and* like slapstick/stupidity) is quite small.
IMO, this is a "burner" book. You take it on vacation, burn through it at the beach/pool while having (many) drinks, and leave it behind. There's no depth and the plot lines and dialogue are weak, so being tipsy makes it tolerable. Unfortunately for me, I didn't read this at the pool/beach. If I had found it in a take-one/give-one library and not known the author, I would have stopped reading when it went fully ridiculous, which is somewhere between 1/4 and 1/2 of the way in, depending on your tolerance for nonsense. Don't hope it will get better and plow through; it gets worse.
So, I'll keep reading Scalzi, but I'll be a lot more suspect about the other books from him I read.