Well, to be fair, I think it's safe to say that Decade failed in its main purpose whatever that was.

Despite our opinions on whether it did the job or not to our satisfaction... it doesn't mean that it wasn't its purpose. While I agree that the series was hokey at best, by the end of the series... it did unify all multiverses into one. I'd like to think that it's the anti Superboy Prime punch.

I took Decade as much more of a TF Universe type concept - seemed pretty clear that each Earth that was shown to him was a different dimension, placing each Rider series firmly in it's own unique version of the same basic concept, except where there was blatant continuation. So, not bringing them together into one, but rather, firmly establishing the same kind of multiverse concept that Transformers has adopted.

Even in the end, it came off the same as the Universe concept...all the key players being gathered into one "middle ground" to decide things as their worlds merged...i got the impression that when all was said and done, their own worlds were all restored and everything set right.

All it did was unify the made up worlds. There was such a cluster fuck of bad writing all through DCD that it made any kind of final story meaningless.

That's true. If anything, DCD explained how those earlier crossovers happened... considering the riders were never shown out of costume. Adding the existence of the AU versions makes things much easier to just overlook.