why phpbb don't develop reliable tools to install MODs?

I'm working on my phpbb forum now,and it's really a pain to expand php with MODs.I have to modify the source code directly to install them.It's just time consuming.I know there is tools like Auto Mod,it's just not reliable,sometimes it can't install MOD for you as you expect,it can't delete a MOD smoothly.Popular CMS like wordpress ,joomla are easy to use,just click to install plugins or modules.Another commercial board software vbulletin also is very easy to expand.Why php don't do that?