There are 3 sides of the ball, and Bo had some pretty awful defenses at the end/offenses in the early days, so did Callahan. Frank went .500 and was on the decline at the end. Did you forget unranked K State beating us 38-9 in 2003? I sure don't, I was there. Do you recall Bo giving up 70 points in a conference title game, and NCAA records in rushing a couple years later? Remember the 2009 offense? Callahan had teams that gave up 70 to Texas Tech, and 76 to Kansas for goodness sake. I don't think what I said is a reach at all. You could argue 20 years instead of 25, but it has been going on a lot longer than 7 years. 2010 I will give you, but that is basically the one example in the last 20-21 years.
I think you have Husker PTSD and memory loss!
To most fans, there is a lot of middle ground between terrible, decent, good, or elite. It can't be all or nothing because the standard would then be National Championship or you are "terrible". Yes, those bad losses happened but so did a lot of good to great performances during those same seasons. I do remember the 2009 offense that had a very injured QB. They still put up 49, 38, 55, 31, and 33 in 5 different games. They weren't terrible but they struggled during key moments- especially against #3 Texas in the championship game. That was all with our Heisman hopeful QB sidelined for the final 6 games with injuries.
Everyone remembers Callahan for being a really bad coach but he was close during the 2006 season. On October 21st, we were 6-1 with out only loss at #4 USC. We played #5 Texas later that day and lost 22-20 in a game that many will remember we should have won. We were a good football team and certainly not Terrible.
2010 Nebraska was 9-1 on Nov 20th and ranked #9 with a 31-17 top 10 win on our record. We played at #18 TA&M later that day and lost 9-6 because our QB was playing on a sprained ankle and there was some questionable stuff outside of that. We were a good football team and certainly not terrible.
2012 we were 10-2 going into December...
2013 was a tough year but we still finished 9-4 and beat top 25 Georgia to end the year...
2014 we start 8-1...
2015 was Riley's first year and it was rough. We still won a bowl game and beat a top 10 team. Maybe terrible but arguable.
2016 we started 7-0 before losing to back to back top 10 teams on the road. we won the next 2 and finished 9-4...
2017 is when the terrible starts.... 4-8, 4-8, 5-7, 3-5....etc
I think you are just remembering the negatives and I think you are suffering from completely unrealistic expectations if you think we have been "terrible" for the last 20 years. There is no question that we have been terrible recently but even Riley's good year wasn't terrible by most standards.