I think the problem is that for many of us, the ONLY trees we got in our first batch of seeds were old variants. If we want the new ones, we only have about 2 out of 6 chances of it, since you've made it so that the old variants are available in the garden. This is the first time (other than Halloween) where this has been the case, so it's frustrating. I don't WANT more of the old variants; if I did, I would simply breed for them. I want the NEW variants, but since there's such a small chance, I probably won't get them.
I don't really want more seed slots, but I DO want a higher chance of the new seeds being the new variants. And that's not what I'm seeing.
I agree, I'm finding this event more frustrating than fun because of this.
My 'problem' is the opposite. I want more burning trees, so I breed a seed and it turned out to be a new variant...