Bands that want to play up already will play up.
Those bands that have limited instrumentation, limited skills, or limited numbers have a very very hard time finding accessible music on the Grade 1 list.
That's why the same thirty to forty pieces are played hundreds of times every year, and why judges get sick of hearing them - causing them to be taken off the list altogether a few years down the road. I haven't checked the Brynnpark page in a few months, but I bet if I went into his results aggregation, there are many Grade 1 pieces that have no or next to no performances in recent history.
If there were more options for imperfect bands, more pieces with unison parts, and more pieces that are attractive to young players, the Grade 1 list would be in much better shape.
This also doesn't even discuss the Grade 2 list - which has a TON of great pieces on it, but of the 219 pieces on the list, 36 are from the Grades 3+ list but are simplified, and over 100 of the remaining pieces (I didn't listen to them all, admittedly, but I've looked at a good chunk in my years) are ballads. For many bands, the options to NOT do a ballad or something that may be way too difficult technically are quite limited if you're required to do a Grade 2.
There's simply neither enough music, nor enough variety on the Grade 1 and Grade 2 lists. No TMEA clinic can fix that - the PML committee needs to make a commitment to changing the makeup of both lists.
And as for your last comment? An "advanced Grade 1" should be a Grade 2. There shouldn't be an "easy" or a "hard" Grade 1. Grade 1 by its very nature should be EASY. This is for unexperienced or underdeveloped musicians. We should be setting them up to learn to make good characteristic sounds and play well, not to perform music poorly. Bands that want additional challenge