I don't think the plans are overly complicated. They are involved, but not more than I would expect given the angles and molding. I don't see any dovetailed miters or anything like that. It seems most of the joinery is rabbets and dadoes. I agree with smallboat with the point that this is supposed to be an heirloom piece. I am sure some 2x4 cleats could be used with some lag bolts and that would be easier and still very strong, but it wouldn't be something that I would consider an heirloom.
When I think about trying to build an heirloom, my priorities go like this:
1) It has to be beautiful. Who is going to keep it and pass it down through the generations if it is ugly.
2) It has to be strong and built to last. No matter how nice it looks, it won't make it through the generations if it falls apart.
2a) It should be made from high quality materials.
3) It helps if it serves a useful purpose.
I don't think ease of construction even makes it onto my list.