Part of the reason is that once you have a sufficient understanding of HTTP, you realise that virtually all the reasons you wanted log analysis are not suitable for analysis. Things like caching make it practically impossible to get number of visitors etc. There are tricks you can do (e.g. cookies), but there are always things that make the tricks unreliable (e.g. people refusing cookies).
HTTP log analysis is good for server optimisation, and not a lot else.