I want to be able to turn on personalized menus (Intellimenus) when in XP Start Menu mode.
Imagine if Intellimenus were enabled with the XP Start Menu.
You use 5 apps; the rest are not used much. (Studies show that 5 is the typical number of unique applications users run on a regular basis. All the rest are rare.)
Those 5 apps are on the MFU.
You decide today you want to run some other app, one of those other apps that you run rarely.
You click All Programs.
You can't find the app because it got chevroned away. It got chevroned away because it's a rare app, by definition ... if it were a popular app it would be on the MFU already!
If you are a naive user, you say "Hey, who uninstalled all my apps? It's missing from All Programs!" It's kind of a misnomer to call it "All Programs" when in fact it doesn't show all your programs.
If you are an experienced user, you say, "Sigh, why do I have to keep clicking this chevron? The whole reason I'm going to 'All Programs' is that I want to run an app I haven't run in a long time, duh. The chevrons should be pre-expanded, save me a click!"
In other words, if we had Intellimenus enabled on All Programs, it would just show you your MFU again, since the MFU and Intellimenus are both showing the same information, just in different ways. That's clearly pointless.
Think of "All Programs" as a really big chevron. The MFU is the collapsed version. All Programs is the expanded version.