Board members are not executives and dismissing the board would have been a disastrous decision. I don't have the list of exec-s that Barto removed and I don't want to waste my time researching it, but one of the former executives was running against him as presidential candidate.
Most of the executive structure was the same. He didn't do any wholesale changes. I don't get where you have that from.
Frexia ran against him and Faus went back to his old job(he backed Bartomeu for the record).
What Bartomeu did well was starting his campaign early already when he called for elections in January, door-door campaign, involving the Penyas and gaining their trust + the media support he had was vital.
As for Laporta's dubious deals then he's not the one who is facing or faced a prison sentence for tax fraud, neither did he get the club charged for tax fraud either(first time it happened in FCB's history btw). So to speak about Laporta's faults and mistakes when you're backing BartoRosell who has harmed the club much more is hilarious and hypocritical.
And socis have always been conservative. Voting Rosell, Bartomeu was just a part of that tradition. If anything then Laporta in 2003 was an exception, an exception that till this day stands as the best President of the club, because he and his team had the vision and balls to take Barcelona out from a dire situation and set the base for what the club is today.
No doubt Laporta's campaign sucked though. Wouldn't have won even if he had a great campaign either. Bartomeu got most of his votes from the senior socis whose support Laporta never really had even when he was voted in and was at the peak of his presidency.