As the sports broadcasters paying heavy amounts, they try to get as many sponsors to recover the money spent, as they can't raise price of the channel beyond certain limit because viewers are not willing to pay that big price.
Now more the sponsors, more the advertisements are been telecasted in available time. Although this doesn't gives reason for this channels to cut the sports broadcast at important stage and show adv's. ESS is very good in that matters of sports broadcast, but some regulation board should be appointed to put check on other channels showing more adv's by cutting sports telecast in between