[MTSCMike]

No I can't site a particular source. When I had my FFL (many years ago) there was already a movement among some dealers (can't recall the national FFL dealer's organization name right now) to lobby for a requirement for all transfers to go through a licensed dealer. The reasons are obvious...it helps their bottom line in a business that is very competitive and has relatively low margins. They even lobbied (fairly successfully) to eliminate FFL dealers who operated from a home based business (non-storefront, non-stocking). I was eventually unable to renew my FFL without proof of a "storefront" business.

I don't blame them for wanting to bolster their business and I simply "assume" there are still several (many) who would like it a lot if all gun sales had to be handled through a dealer.

If that reasoning is too slim I will edit and withdraw that comment from my post.