The answer is they were simply more accessible at the time, if we had reached out we could probably have gotten an interview too. but at the time, b182 actually had an exclusive interview with Tom a few weeks before, but it wasn't anything significant, they asked him a bunch of non interesting questions, but then they asked Mark the hard hitting questions a few weeks later, and thats when the revelations truly began.
If anything, mark was far LESS accessible back then. There was no twitter, tumblr, or facebook. You could go months without hearing a peep from a band member.
The only reason that interview happened was because mark wanted it to happen. He needed to come out and talk about everything. b182 was the most popular blink news site of the time, so they were an obvious choice.