When a company understates the problems of their product and overstates the issues with a competitor's products, we usually consider that a day at the office. But when Apple does it, it's "losing their credibility!"
Apple isn't a neutral party here, and they're allowed to advocate for their products. If you disagree with the arguments they make, well that's why we have blogs, magazines, newspaper columns, twitter, etc. But don't tell me they're 'losing their credibility' because they have the nerve to portray their products in the best possible light.