Some users mentioned that enabling too many addons, will cause lots of tabs to be enabled (mostly in the 3D View) and then become very difficult to browse the panels. Personally I haven’t faced something like this yet, but the only way I can consider this happening is by shrinking the Blender window size enough so the same effect is replicated.
For the record, trying the same on the tools (left side) is no problem because there is a scroller already.