Four Island

This always seems strange to me. Why do most people on the internet that provide software packages, such as Linux packages that do not have standard distribution formats, or PHP sites like Wordpress, always distribute their software using gzipped tars? As in .tar.gz

I mean, really. Bzipped tars (.tar.bz2) are a much better way to compress things. Bzip2 is a much more effective compression algorithm than Gzip. I always use bzipped tars to archive my data.

Or wait. Is there some kind of deficiency with the algorithm that I don't know about? Am I going to wake up one day and find all of my backups useless? Oh dear, now I'm scared. :)

So, what is with bzip2? Is it just that people can't be bothered to switch to it, or is there some huge bug that'll eat Four Island?