Let's assume what you say is true, and Busch was the 3rd choice. If all three guys you are considering are similarly excellent choices, what's the reason for negativity if you get Busch?It can be two things at once. I don't think Busch was the first choice. I also think he'll end up being a good hire if he's allowed to be.
I think it was unreasonable to expect the ST coach to be announced very early in this process, even if the decision to bring in Busch was likely made earlier. Frost said he wanted the OC to have input on the other offensive coaches, and presumably the structure of their roles. Even if he was 90% sure he wanted a full-time ST coordinator, the option was still there to structure things differently. Busch was already here, and already has a commitment to Nebraska. It would have been illogical to reduce your flexibility with the structure of the staff until you knew the other pieces with more certainty.
The delay certainly didn't prevent them from attracting two quality specialist transfers. There just isn't a downside to being patient with the process if you already have Busch in your pocket. I don't understand the need to jump to a nefarious explanation, other than to find a way to inject this announcement with unwarranted disappointment.
This fanbase is mentally ill from the way the last few years have gone on top of the decade before that. You can see it when reading fan forums. Pre-emptive pessimism is a defense mechanism, but it sucks all the joy out of being a fan.