Iforgive the choice of phrase, but how often can you poorly execute something, before the concept is damaged?
If you do the exact same over and over again expecting different results, sure, that's the definition of insanity. But this is a group dynamic and works much differently. There are tons of characters in the X-Men and Avengers I love in the group, for example, but would never purchase a solo series of.
As you also point out yourself, "poorly executed". Besides this movie which may not be "poorly" executed (haven't seen it, don't know yet), there is a new TV series being created for next year for the Hulk (Guillermo del toro is putting together the pilot!) and I'm sure there will be more movies and cartoons.
Whether one (personally) hates the character or not, it is FAR from a damaged product. The character has been around since the 60's and will continue to do so long after we're dead.
These are characters that are bigger than poorly executed media endeavours, and besides, not all outtings can be duds, some of them will be well received by the majority (since I'm only assuming this is the way we're measuring this, since personal satisfaction or hatred is too limited and individualistic)