Part of the reason for the bloat is that newer syscalls replace older ones (with the option for keeping the older one around for compat). So, open becomes openat (since the latter is more expressive). Also, over time, different data types grow to allow, for example, larger than 2G files, which has a big ripple effect on lots of system calls. But looking now, a lot are due to MAC and ACL functions (well, 30). There's 80 'at' system calls (though some are in the ~150 obsolete list)... So it isn't as utterly horrific as it might sound, but it's still pretty bad. (There's 400 defined, with 20 of those being for prior versions of the OS).

Warner