I've been mostly out of the thread for a few days--diving! I'm glad to see the tone has turned polite again.
I'm happy to agree it's "overkill." Much of DIR/GUE could be seen as "overkill" in my opinion, and that's not a bad thing. One could say you over-train, over-prepare, over-reserve gas, and then when the SHTF there is a high probability you will be fine. There's a saying that goes something like, when the SHTF you shouldn't expect you will rise to the occasion but rather you should expect you will sink to the level of your preparation. Neptune forbid I get a few minutes less bottom time than other divers or have to deal with a bigger tank on my back to meet the minimum gas requirement!
As for the slow, stepped ascent that GUE refers to as a "minimum deco ascent," I believe the only aspect that is arguably advantageous over a traditional direct ascent is that it may help the divers maintain control; less likely to snowball into an uncontrolled ascent. I believe Boulderjohn has pointed out that from a deco perspective it's probably equivalent in net effect to an ordinary safety stop. If somehow, despite all the preparation, a diver runs out of gas or has a catastrophic reg failure, the team should be able to ascend calmly using the same minimum deco ascent they do all the time. That's best case--what you aim for, what you train to do. If, in all the excitement, the team misses one or two of these non-obligatory stops it is unlikely to spiral into an uncontrolled ascent, and they will still be okay. Or if the team is ascending with a distressed diver who isn't trained this way, they could still manage a controlled ascent and surface with plenty of gas.
Yeah, some aspects of the DIR/GUE system may seem like overkill. I like overkill.