Chalkster, you'll never convince the "no tails" on this one m8.
It does partly come down to money, perhaps more than ego in having something "exclusive".
As others have said finding an unknown record in this day and age is bloody hard work, bloody expensive and a massive gamble, not comensurate with the modest DJ fees that most have to endure on the northern / rare scene. It's this point that the "old romantics" who thought it was "all good fun and part of the rough and tumble of the scene in the 70's" (a time when new discoveries were being found every week and records were turned over much faster), lose the argument.
Put it in perspective - a new discovery back then was roughly commensurate with a DJ fee for an hours "booking" - some a bit more, some less. And there were always good new discoveries waiting to be had on trips to the USA, Soul Bowl etc. These days a new discovery is a rare event of itself, and is likely to be 10 times a DJ fee for an hours booking, sometimes more, if you consider (unless you get lucky) some genuine new discoveries going for £2k etc. A hell of a lot of money in anyones book. So whether the purists like it or not the DJ is investing a lot of money in something new far more than their colleagues back in the 70s ever were for a single piece of vinyl. So I do understand why that DJ would want some exclusivity in it.
And then with the internet opening up access to every mom and pop in the USA, unless it's an acetate, the new discovery may well turn up in some form of "quanity", so suddenly your expensive exclusive "newie" is being hammered by everyone else / mis-credited as their discovery etc.
Anyway having said no chance of convincing others, I am not sure why I have written the above .....you either get it or you don't.