Well, sex sells. Sex like many other basic needs remains one of the most fundamental drivers of humanity. That's just the way marketers are exploiting our inner consciousness to generate profits for their clients.
The best way, I feel to change the sexualization and objectification of society is to stop consumption of such content. On an individual level, we may not have much impact to change the outcome. However, collectively, we can at least bring greater awareness to stop such marketing practices.
Then again, who would voluntarily stop consuming magazines plastered with beautiful women?
Yup, power is in the consumer.