I think there is a little more nuance there than you are giving credit for. As three former GM's discussed on the podcast, there were relationships built over time with counterparts, and you understood their mission and what they were trying to accomplish. Hahn talked about GM's he enjoyed dealing, based on how they conducted their dealings and what the ultimate purpose was, and all three hosts discussed frustrations with dealing with GM's that seemed to be more interested in fact-finding missions and information gathering than ultimately wanting to close a deal.
Nightengale offered very little detail in his statement behind why teams may have been getting frustrated with Getz, but I would put good money on the fact Nightengale isn't just making up that anecdote. It would be very safe to assume 2-3 GM's told him that, and he felt confident enough to put that out there, given what he had heard. Again, doesn't get into why they were frustrated with him, and as I said earlier, I'm not using it as a shot against Getz at this point, none of us have enough information to go off of on this specific topic to form an informed opinion or take a passionate stance on the topic.
But I personally don't believe when it relates to Robert/Getz and the trade deadline, GM's were getting frustrated with Getz simply because of the high ask. That happens every day in GM conversations. And if a team won't move off those asks, then they end up keeping the player, pretty simple. I take it as more related to what was discussed on this podcast. Mixed-messages sent by a GM to another team, a willingness to deal then all the sudden pulling back the offer, or spending a lot of time on something that continues not to make any significant progress....could be a lot of different things, and I think a lot of those skills get sharpened over time. Some people are very natural in negotiations, but as a former player like Getz, trade conversations with other GM's, GM's that have been in their roles for a decade+, that has to be an acquired skill that is learned over time.