Why would those users who want to have the window open up in the same position every-time move said windows' positions after they've opened?
I like some channels to open in specific positions, however every so often I use the cascade or tile options to organize windows slightly differently for a different view and I later use the reset position to reset them all back to their saved positions. I am sure that other users use them in other ways.
MDI applications are intended to run maximized.
And that is why MDI windows have a built-in cascade and tile feature? :-) They are not intended to run maximized but they do have that as an option. I very rarely have my MDI windows maximized and instead prefer to have multiple windows visible at the same time in different positions. However, I am sure that other users do prefer to open them maximized, that is why I added this most recent feature.
The solution to this would to be disable MDI completely
mIRC already has that option, it is called compact mode and allows you to open all windows on the desktop. It is an option because many users, including me, prefer MDI windows.
In this day it's odd that such an option to "remember" window positions
It depends on the type of application. Not every feature is applicable to every type of application. In some applications it might make sense, in others it might not. I personally do not think it make sense to clutter your mirc.ini file with hundreds of entries for channel and query window sizes and positions that you only joined once and will never visit again. It's all about finding a balance.