Well, it seems to me that a scrollable list was more interesting than a huge box without scrollbars, I can perfectly understand why Patchou would use scrollbars. But as you say, it may be frustrating to scroll every time through your list to look for an emoticon.
However, in Plus! Live you can create your own emoticon pages. If you open the Quick Emoticon panel and click on the little down arrow in the top right corner, you can click Settings. There, you can create a page by clicking New, add the emoticons you want, sort them and give the page a name. This way, you can sort emoticons of the same set in a separate page and find them easily through the drop-down list, like this:
quote:
Photos - contains all emoticons of photos
Middle fingers - contains all emoticons of "f*ck you"
Love - contains all emoticons about love
...
This method may take some time, but in the end you'll see that it can work lots faster than you could in Plus! 3.