Well, yes and no. If it is a separate bucket of availability, then passholders might have just used theirs up sooner. Even if Disney allocated 50% of slots to passholders, passholders could still "use up" all of their slots, while resort guests and other ticket holders might still be able to make new reservations.
I'm not saying that's "fair." I, personally, don't think Disney should separate buckets for different types of guests. But I am a passholder. If I was a resort guest, I would assume and demand that Disney let me into the park every day of my stay. And if that meant keeping Passholders from getting reservations, then I'd be fine with that. My justification would be "they can always come some other day, but I can only go during my trip."
As a Passholder, I wonder why Disney doesn't offer a bundle of tickets with reservations with resort stays, and/or require people buying tickets to specify what dates they would be using them. If the day isn't available, you cannot purchase the ticket.
Then, you don't really need separate buckets, but you can hold back some availability until the last minute to accomodate people whose plans change or who decide to go at a spur of the moment.
There's a lot of ways Disney could do this better than they currently do. Hopefully, they will continue to improve this system for the benefit of all guests. It will be hard to make everyone happy, but publicly stated commitment to fairness, openness and transparency, with clearly stated rules and limitations, would be a great start. Then, honest and sincere follow-through on those commitments.