I can't find that critique with Google.

As I said, the style is very terse, and I have my suspicions that this is by design to minimize the number of less-qualified programmers trying to submit sub-standard code back to the project. (Edit: since it's been 10 minutes and I still can't reply to tomalsky's comment, I should point out that my "suspicions" are a joke; read the linked code sample and judge its quality for yourself.)

I have dived deep into the samtools code, rewritten chunks of file I/O inside it, messed with alternate formats, and my personal experience is that it's been easier for me to change, adapt, and understand it then any other open-source C project I've tried to dive into, such as, say, GNU join.

If anybody can point to where samtools is using many more cycles than it has to, please let me know! The worst part about it is that the compression and decompression is not multithreaded, but that is being worked out, I believe.

samtools is among the better software in sequencing-data analysis. It is also great in defining formally the file format it uses. The same cannot be said of many other tools. For my recent work in RNA-Seq, samtools is the most robust and trustworthy tool I looked at and used, and I looked at almost every popular tool, the major exception being RSEM. If only all bioinformatics tools are more like samtools.

It works just fine. And iterating through files is not rocket science, anyway; it's not hard to follow what is going on.