We have beat this issue to death for years now, and while the KDE team has actively made a lot of effort this time around to clean up a few things, the problem does remain. Konqueror's context menu is a mess, why would I want to zip a web page or use Cervicia with it, is beyond me. And the main menu itself it just has way too many options. Konqueror is the Frankenstein of file managers, made of so many Kparts that the end result is just not good. Options of other Kparts are appearing on the main and context menu etc.
Additionally, there are too many apps shipping with KDE. This results in a huge KDE menu (while other options have been stripped out of KMenu in this version). I don't need four text editors in the same submenu (Kate, KWrite, Kedit and Kommander-something), I need one. While each one of the four have a bit different specialty (e.g. Kate is a good programmer's text editor) the fact remains, there should be one solution offered. KDevelop should do the rest of the job for the programmers. The second-tier applications should be offered separately via KDE's web site for those who want them, instead of bloating the main KDE distribution.
And then there is the still terrible Kontrol Center. The KDE project seems to have acknowledged the problem because they now offer custom Konqueror views (like Gnome's "Start Here") and so this new trick gives the impression to the user that their control panel is leaner. But it is not. It is an... eye illusion and if you actually load the normal Kontrol Center you will get even a bigger tree with more modules than on KDE 3.1. The problem is not just that there are too many modules there, but there are two more problems: 1. Each module has 2-5 tabs full of widgets and stuff. TOO many options, too confusing as to what is where, too much bloat for features that are redundant for the vast majority of people. Too much detail. 2. There is no integration between modules. For example, there should have been a single module for keyboard and mice, with one tab for each with some basic must-have options there. Another example is that we have the theme-related modules spawn on several modules under "Appearance," ranging from icons, color, style, etc., etc., instead of getting a single panel for all these related items with the most needed options listed there.
Some of the options found on preference dialogs should not be there at all, but work automatically. For example, I used a white-ish background image and then I couldn't read the text on the desktop icons. KDE should have either detect the background image color and automatically adjust its icon text color all by itself, or do it the "easy way" as Windows does it and apply a dark text shadow by default. Currently, the user has to literally search on panels after panels where the "show text shadow" option is hidden (FYI, is on a panel after you clicked "advanced" on the background image panel) and when you actually find it next to more redundant options and you set the shadow as ON, it just doesn't look good and sharp. It looks like a "mountzoura," as we say in Greece: a blot.
Also, I would advocate for some Qt UI changes, e.g., expanding a few pixels the space between words on the application menus. Currently, they read like a sentence instead of being wisely spaced out. Also a soft line that separates the menu from the toolbars and the toolbars from each other would have been nice too, as currently they look like they have all been thrown out together with no easy way for the eye to distinguish them fast enough. See one of my screenshots to see what I mean.
Another thing I dislike is that "settings" menu that most KDE apps have, where they list 3-4 different "Configure" options in addition to the "Configure the application" option. All these configures are confusing and severely bloat the app menu; they should not be there at all. For example, the "configure toolbars" should be accessible by right-clicking the toolbars themselves for example, a-la OSX or Epiphany. The "configure the app" should be just called "Settings" and put under the Edit menu when applicable. ("Configure" is a verb and as I said in the past,is like ordering someone to do something that has never done before. UIs is about psychology too and the right wording is important).
All the above might sound like nit-picking, but rest-assured, pixel pushing, looks, user psychology and usability is a huge part of any desktop environment. And KDE is one.