That's kind of an oversimplification but yes, a 10-8 record this year could easily be worse than a 6-12 record last year.
By Torvik (which isn't exactly the NET but it's close enough and easier to look up) of their 12 losses last year, 6 were to teams in the top 25. (Also their two non conference losses were both tournament teams.) And then they beat teams ranked 35, 23 (twice), 20 and 17.
We lost two non-conference games to teams that aren't going to make the tournament, one of them by 24 points, and our best win is #37.
But that said there is still a decent chance we make the tournament at 10-8. Texas was one of the very last teams in the field last year and played in the First Four. Nobody is saying we don't make it at 10-8, we just probably won't be breathing easy until we see our name on the screen.
You're too focused on the lack of bad losses thing, the committee has fairly consistently been willing to overlook one or two bad losses if you have several good wins.
Our situation this year is a lot less about who we've lost to than it is who we haven't beaten. Like we were a FOUR seed last year and went 11-7 in league play.