I'd refer you to this quote, from DeWitt, said to Goold.
"We’ve done a lot of things to get where we want to go, and we’ll continue to do whatever we feel is necessary and appropriate to make the playoffs and once we get there do as well as we can. If it happens this year, which we certainly hope, it will be exciting, but we’re still going to try our best in subsequent years to make the playoffs as well."
That explains the Cardinals' stance.
I think the one-game wild-card playoff should be changed to three.
More games. More money. A better chance the better team wins.
As for what the Cardinals should consider success?
I just think they leave too much up to what-if.
The best example was the trade deadline.
The Cardinals didn't add a starter because they worried about the future, worried about losing prospects that could come back to haunt them.
Those prospects can be replaced, via trades or free agency, or international signings.
I wonder, in the era of superteams that have gotten fat by tanking, if sustained success can win it all.
I think it's fair to question this without dismissing the success that this group has achieved.