First my disclaimer: I don't think bonus boxes need to be made easier, and I have never run for one and quite frankly probably never will. So discount absolutely everything I say here.
People like to say that distance isn't hard. I've heard this time and again from people who do well with distance. The reality is two fold: 1-) Anything can be hard for a given dog and handler team, based on challenges of the individuals and, relevantly here, 2-) Anything you don't have access to training for is really freaking hard.
Distance - any distance, even Novice Chances - requires at least some foundation training skills to be successful at. At Novice, you can mostly, with most dogs, get away with general agility training foundations and verbals to make it work. Beyond that, you start needing both more confidence and obstacle commitment in the dog, and some handling changes. The further the distance grows, the more skills the handler and dog both need.
If there is no one there to guide and teach you, and your only exposure is watching other people occasionally run it, it may as well be magic. A lot of people aren't just missing the skills for bonus boxes - or access to get those skills!- they are missing the skills and access to training for **Chances**, period.
That isn't to say I think it needs to be made easier, but I do think you need to accept that large portions of NADAC's competitors, even those who would like to do it, simply aren't going to have the skills to. There shouldn't be a mystery as to why the competitors aren't there/new competitors aren't coming in.
I love NADAC. I love agility. I cannot teach myself to do bonus box handling. I don't have a dog ready for it, but even if I did, it's not something I'm going to figure out on my own or through watching other people. And a whole lot of people are in that boat - some of them with the bonus boxes, some of them with distance lines, some of them with elite chances, some of them with chances at all, depending on what kind of training they have access to.
Saying 'just challenge yourself' is all well and good, but when you don't have a clue where to start the challenge is a lot closer than the bonus box lines. And that's before accounting for individual dog/handler challenges beyond training access. I don't need a thing needs to be made easier - I like my challenges, dammit, and quite aside from that I recognize the Bonus program as one that's for the truly elite and not me - but... awareness and compassion are good things.