To me the biggest gripe you can level at Sipple (and Christopherson, and McKeever, and Rosenthal, and Heinrich... not sure how you differentiate between them all when they cover the same team from the same news organization) is that they put the kid gloves on too much. I guess that's because they work in such close proximity with the coaches, even Callahan's regime, that they feel like they can't burn bridges by exposing too much.
That's not a Sipple problem, that's a problem with everyone who covers Husker football, though. "Telling it like it is" is a pretty broad statement. If you've got specific examples I'd love to hear them. From what I've read, Shatel tells it like he sees it without a lot of proof. He's as much of an "insider" as the people who post here, and he has generally less proof. Christopherson is a good writer and a fine journalist, but he's no different than Sipple in "telling it like it is."
Journalism is all about cultivated relationships. Nebraska football is Sipple's bread and butter. Yeah, he could expose a lot of things, and he'd get great readership on those articles, but he'd be persona non grata at every news conference from that day forward, pretty much killing the duck that lays the golden egg for him, and potentially the rest of his staff.
Let's put it this way - I talked to Sip at the tailgate and asked him some specific questions about some specific situations with the program. 1) He knows the real story on all of the things I asked him about, and 2) he won't disclose them in the Sports Section because (surmising here) it's not worth one story to destroy a source.
Now, you want to proffer Shatel as a "better" journalist than Sipple, and I'll question your sanity. Christopherson... again, I like Brian, and for a brief moment I got to meet and greet with him at the tailgate as well, but "better" than Sipple? I don't see it, and I don't see at all how he "tells it like it is" more than Sipple. Their take on things is largely similar, especially since they run their articles through the same editorial filter. Dirk Chatelain? I like what I've read from him, but I can't speak authoritatively on him as a writer. Lee Barfknecht is pretty much a potzer, and frankly I've seen little from him that makes him a "good" journalist. He's average.
Bottom line - if you're going to proffer the notion that criticism = "good journalist" then you're not talking sense.