The Brawn GP owner, whose team top both the drivers’ and constructors’ standings with two wins from two races, told reporters at the Malaysian Grand Prix that his rivals’ difficulties were a direct result of last year’s title battle.
"It is a reflection of what has gone on in the last year or two," said Brawn, the former Ferrari technical director who guided Michael Schumacher to seven titles with Benetton and the Maranello team.
"McLaren and Ferrari had a championship to fight over and I can understand that it was very difficult for them to say ‘Look, we’ll stop pushing this year and put our effort into next year’."
The sport has introduced major changes, with slick tyres and completely revised aerodynamics as well as the new KERS energy recovery system.
Instead of being able to carry over developments, designers have had to start with a clean slate and come up with new solutions.
Hamilton, the 24-year-old who last November became the sport’s youngest champion after beating Ferrari rival Felipe Massa by a single point in the final race, has just one point to his credit so far in 2009.
While the Briton would have scored more had he not been stripped of third place in Australia for "deliberately misleading" stewards at a post-race enquiry, his team mate Heikki Kovalainen has yet to complete a lap.
Ferrari, who secured a record 16th constructors’ championship last year, are last in the standings with no points — the Italian team’s worst start since 1992.
While McLaren recognised before the start of the season that their car lacked pace, Ferrari have suffered some self-inflicted wounds.
At Sepang they kept Massa in the garage during the first session of qualifying, in the mistaken belief that his time was fast enough to take him through, and went too early in switching Kimi Raikkonen to full wets during the race.
Contrarily, those teams with uncompetitive cars last year, such as Brawn’s now-departed predecessors Honda, started work on the 2009 versions much earlier than those fighting for the championship.
"For us it was a very easy decision. It wasn’t a clever one, just a very easy one. We didn’t have a very good car so why waste time on it?" said Brawn.
Brawn’s team has also been helped by a controversial rear diffuser that rivals say goes against the spirit of the regulations and have protested.
Stewards in Australia and Malaysia have already declared cars fitted with the ‘double-decker’ rear diffuser legal, but an appeal court hearing scheduled next week in Paris could rein in pace-setting Brawn GP, along with Toyota and Williams.
Brawn, along with Briton Jenson Button, who led the team to victory at Sepang on Sunday after his triumph in the season opener in Melbourne the week before, expects McLaren and Ferrari to fight back strongly.
"They are both very strong and fantastic engineering companies so they will sort it out," said Brawn.