How can Brazil for from Senna to?

You're doing a couple of good Brazilian drivers a disservice, as well as failing to recognise that in Fittipaldi, Piquet and Senna Brazil produced a run of great drivers which no nation other than Britain or Finland has ever managed to put together in such a short space of time. Having an absolute top-line driver come along has been the once-in-60-years exception for most other countries, so having a bit of a break after sending three of them to F1 inside 15 years isn't surprising. Brazil is lucky enough to have produced drivers like Barrichello and Massa in the intervening period, both of whom could (should) have been a world champion...they were certainly better than a few drivers who did win the title.

Due to the success of Fittipaldi and Piquet, there was a period in the early-to-mid-80s when being South American opened a lot of doors in motorsport in Europe which refused to open for people from other places (much as happens for Japanese, Indian and Russian drivers today, but driven by success on the track rather than sponsorship). Senna was one driver to benefit from the rush to find the next South American superstar...others who got the same leg-up included Raul Boesel, Mauricio Gugelmin, Roberto Moreno and Chico Serra. I'm sure you'll agree that while those last four were mostly solid drivers, none of them were quite at the level of a Barrichello or Massa.

So to conclude, Brazil not producing an all-time great since Senna is neither surprising nor worrying. It's exactly what the majority of nations have done for a large part of the history of F1. If things like nationality are important to you in choosing your F1 heroes, then support the best driver you've got available to you...he's doing what he can with what he has. Without Massa, the nearest thing Brazil would have to an F1 driver is Luiz Razia...

I think you are being unnecessarily harsh in describing either Rubino or Massa as 'clowns'. Rubens was always under the shadow of Schumacher, for sure, but he was never a clown. As for Massa, much as he's not been the same driver he was before his crash, again he's no clown. All I can say. Much as I don't understand totally, what you are asking.