I have had bare bucket cutting edges, a reversible cutting bar, and a tooth bar on my buckets. Both the cutting bar and toothbar add strength to the cutting edge and prevent damage in my opinion. I've used the toothbar to pop out a lot of roots and never had even slight bending of my loader bucket. Of course, I bought the "heavy duty" bucket instead of the lighter weight "standard' bucket.
My HD buckets come standard from the factory with holes drilled to mount a reversible cutting bar and holes on the side of the bucket for toothbar mounting. New Holland also sells both cutter bars and toothbars with a factory part number. Of course, New Holland doesn't really make their compact tractor loaders. They get them built to their specs, but they are not built in a New Holland plant. The key with NH is that if you buy a HD bucket, it will come with the ability to add cutter bars and toothbars. However, the standard bucket is not considered the best for these addons and therefore are not set up for them. This infers what NH will support with warranty, the HD bucket only.
Finally, if a manufacturer built a bucket for every need, their inventory would be doubled or tripled. They build a plain bucket that can have the features added to the customer's needs. That way they have a lot fewer buckets and and the addons are built to fit a lot different platforms. It's simply a case of keeping the most options open with the minimum inventory.