Why can't a member of QPGMR change their password or run WRKSYSACT?

I guess this is a little bit philosophical.

So I have a client that gave me greenscreen access. I have greenscreen and
PASE access. I can start and stop mysql, I can run wrkactjob. I can ssh
into PASE and do my unix things. I'm not qsysopr, qsecopr, or anything like
that.

I can't change my user profile password. This seems to be the default way
of things according to google. That makes no sense to me. On windows,
linux, most RDBMSes I use, and most web apps, one can change their own
password, and is encouraged to weekly. What is rhe wisdom in not letting a
programmer change his own password?

Secondly, and this is actually no surprise to me since I learned this when
I was an operator circa 2003, why can't a programmer run WRKSYSACT? Its the
equivalent of taskmanager on windows or top on linux. I know its a little
bit of a heavier command (and I'm ignorant of OS/400 internals to
understand why, but I accept it). However, I have access to wrkactjob, so I
could write a program that does what wrksysact does, but more
inefficiently. Also, I could tie up the CPU through other methods as well.

So why?

Justin