I'm not really that surprised or disappointed that Dragon Ball games are on the decline, in terms of release-cycles
and sales. It was bound to happen sooner or later...
I mean, there have been
32 Dragon Ball games released in North America over the past ten years. Not to mention, the Dragon Ball TV series has been over since 1996 in Japan where it counts, and efforts to revive it once more via Kai have proven unfavourable (obviously... they couldn't even finish the series).
My feeling is that the Dragon Ball series, if it is to continue at all, needs to move on in a big way. Create a TV series (with Toriyama's direct involvement) around the Dragon Ball Online time frame or something else entirely that relates to the DBZ universe, and produce a few more movies/specials. It has had an incredible lifespan on the coattails of the ancient Dragon Ball Z of yore, and the only legitimately original, new canon material in 14 years have come in the form of one special a few years ago. If new material were to be released, and done well, who knows... it could rejuvenate the Dragon Ball fandom another 14 years and present new video game opportunities (also with the amazing feature of having a story mode that hasn't been recycled a billion times

).
At this point for me personally, it's a miracle that I'm not entirely sick of Dragon Ball games outright, however I feel like, having actually played all 32 of those games released as well as a dozen or so others never released in the states, that I'm finally willing to close the book on Dragon Ball games. Many of those games were piles of shit, but there were a few gems here and there that I feel can satiate my dwindling Dragon Ball appetite when I need it.
There's a decent chance that if there are any more Dragon Ball games released (which there will be), I won't bother with any home console releases... I hear a 3DS Dragon Ball game is under development and I may give that a fair go if it shapes up to be something worthwhile.
Thanos before Thanos was cool.