The curse of the 6?!

The Electronic Entertainment Expo (E3) is almost upon us, and last year I can remember anxiously awaiting information on one stand-out title for the Playstation 2: Gradius 5! Fans of the series were hyped to see what information Konami would reveal to the public during one of the most important seasons of a gamer's schedule: early May. Rumors of a Gradius "project", most likely Gradius 6, had surfaced on the internet, but nothing concrete was put forth, and.....even though I was trying not to mention this hoping it wasn't true....latest news is that the PS3 Gradius project has been put on indefinate hold. As of this writing, there is no information from Konami about any E3 showing of a Gradius project, which they probably would mentioned if there was even the slightest bit of progress.

This brought to my attention another popular shmup franchise that crashed and burned right before part 6 could get off the launch pad: obviously I'm thinking of Tehnosoft's Thunderforce. TF6 was in the planning stages, and there is even a FMV video that could have been the opening scene to the game on Sega-16's site.
Link: http://www.sega-16.com/Forgotten%20Franchises-%20Thunder%20Force.htm

So what is keeping the number 6 from appearing next to a shmup title?! Sure Gradius has it's spin-offs and Thunderforce has fan projects in the works, but I'm talking about a company supported direct continuation of a storyline. If it's ever gonna happen, it would have to be through one of the founding fathers of the genre - and since the Technosoft team fell off the face of the planet, I'm looking at you, Konami. Forge ahead and be the first company to break the curse of the shooter "6".