I don't see the business sense in that, from Disney's perspective.
I think they ROFR because they see something that they know they can resell at a good profit. I'm sure they have waiting lists of customers that want to add on at various resorts, and when they see something come up that one of those customers wants, and is a deal that makes them a tidy profit, they ROFR it. Yeah, I know that's an oversimplification, and there's other reasons they'll grab a contract.
I think most customers who buy resale are doing so because they've done the research and are convinced that resale offers them the best value. If I got ROFR'd on a contract I was trying to buy, the last thing I'd do is spend thousands of dollars more to buy direct from Disney. I'd simply look for another resale contract that fit my needs. And I think that's what most people do....sure, there are a rare few who get emotionally caught up in the purchase, or can't stand the waiting, and decide it's worth paying a big premium to get what they want right now.
So why would Disney ROFR just to lure a resale buyer into their clutches? It wouldn't work very often, and they'd be purchasing an asset they may not have a buyer for in the near term.
I've even heard it suggested that
DVC ROFR's out of vindictiveness - some people think their guide snatched the resale contract away from them because they 'lost' the customer and wanted to get back at them. That makes no sense to me at all. I work for a Disney-sized large corporation, and believe me, if anyone here spent thousands of dollars of the company's money on personal revenge, they'd be marched out the door by security before lunchtime.
Disney spends money because it benefits them to do so.