I wouldn't have thought Waves plug-ins were appearing more and more like free plug-ins. Many free ones are horrid-looking. For Waves, as from what I've read and felt, it's all about human flow. When the first Q10 was released, the main concept was set that you could simply click-drag a ball on the EQ graph and adjust it quickly. Obviously, you can accurately adjust nearly (if not all) settings on a Waves plug-in by double-clicking on each control.
There's also many 'emulation' plug-ins Waves offers, which not necessarily are powerful, but offer up a very closely mimic'd hardware emulation of products from Neve, SSL, UA, etc. What you're paying for there is all the talent and hours spent getting those emulations to fool their respective hardware owners, much less the Waves customers.
It's all about what you
don't see, however, that makes Waves so powerful. Take the CLA, Kramer, Maserati, or JJP Signature plug-ins. Simple, they appear. Complex and powerful they are.
Now, that I said that, there just might be some ugly-as-sin free plug-ins that offer some serious power. I just can't immediately think of any.