I am guilty of buying too many plugins, and eventually stop using some of them.  Usually that cessation is for an entire suite of plugins I got from somewhere I liked better (like replacing Blue Tubes with UA for example -not that Blue Tubes is bad)
 
It would be so much easier to deal with suites of plugins you may not currently be interested in (though you might come back later - as I did with a handful of the Blue Tubes) if you had the option of sorting them by manufacturer - in the center section of the PIM.   
I tend to organize my plugs by manufacturer, not by function, in the right hand side, then sort by function under the manufacturer.  So If I had 6 reverbs and 8 compressors and 7 eqs from UA, I would have UA folder, Reverbs Sub-Folder, Compressor Sub-Folder...   
I would guess it would be too hard to sort by function other than by eyeballing them. Things like the Delay Llama (which I do not own, but now must have !!!) might give themselves away with the name, but so many of the other names are obscure.  
 
Just a thought.  

In the plugin bin's options you can set it to sort by manufacturer...

I'm pretty sure the synth rack as well.

The top level manufactures menu also doesn't allow jumping to a particular alphabetical beginning name by hitting the appropriate key such as 'W', where the subsequent plugin name menu does. - That's criminal.

I can think of at least 3 more-useful sort orders:
1. Last-used date, to identify plugins I haven't used in a long time
2. Usage frequency, to identify plugins I've never used
3. Install date, to identify plugins I've forgotten I had
 

bitflipper
I can think of at least 3 more-useful sort orders:
1. Last-used date, to identify plugins I haven't used in a long time
2. Usage frequency, to identify plugins I've never used
3. Install date, to identify plugins I've forgotten I had
 
 
+1  
This is me too. Especially #3  :)