Some random thoughts on hoarding...
I told my wife that for my midlife crisis I could either collect/hoard bikes and bike stuff OR I could go buy a red Mazda Miyata, get my ear pierced and get a tattoo, the choice was hers. She chose the bike habit and I think that she regrets it now.
As far as which bikes to keep and which bikes to unload you could use the standard "Ride/Wife Comparison Test" or RWCT as I like to refer to it. For each bike that you have ask yourself this question "Do I ride this bike as much as I ride my wife?" If the answer is yes, keep it. Otherwise, it might be a good candidate for craigslist, ebay, garage sale, etc.
The debate around hoarding and collecting usually neglects one of the most fundamental questions in life which is this: Is it possible to have too many bikes?
Answer: Theoretically, yes but in practice no. I've explained to my wife several times that the only way that I could have too many bikes is if I had ALL the bikes. I don't have all the bikes, therefore, I don't have too many bikes. It's a simple principle.