I don't know where you're getting that. I like LXDE well enough. The only laptop I have running Linux runs Lubuntu. I would not call it "very" customizable. I can't easily rearrange the menu (which I blame the retarded .desktop file standard for), I can't add my own menus (to my knowledge), I can't change the application menus to be mac-style top-of-screen menus like I could in KDE 3, etc.
I meant that from a point of view of comparing it to others like gtk3, unity, cinnamon etc for some specific features that I find useful.
Of course, not all distros will lend themselves to all types of customizations easily and customizability, at least to some degree, is relative.
With that in mind, yes, maybe I should tone it down to 'customizable,' instead of 'very, very customizable.'
For instance, why do we need one single global menu with all the apps categorized according to a .desktop file? That's overcomplicated and restrictive garbage.
Here's a simpler alternative: let me place as many panels on the desktop as I want, let me place widgets on the panels, let one of those widgets be a button that presents a menu-ized view of a folder structure. Now I can have as many menus as I want, with whatever layout I want, and organize my application launchers as best suits my workflow.
I used to use Gnome Do as my primary launch tool. Now I just use a shortcut (Windows Key + Space Bar) for the 'Run' dialog (usually found by Alt + F2) and I know the first few chars of my favorite tools after which they autocomplete.
For everyday use, it's hard to beat the speed and simplicity of that.