The claim that Jerry has been a mediocre GM over the past 15 years or so isn't outlandish by any stretch. It's supported by the team's record over that span.
However, during the second half of this season, it does seem as if the worm is starting to turn. The team looks to have better depth. The culture looks to be changing. For those reasons alone, in terms of coaching and talent acquisition, the organization shouldn't make any substantial changes in the off season.
"Many of the greatest things man has achieved are not the result of consciously directed thought, and still less the product of a deliberately coordinated effort of many individuals, but of a process in which the individual plays a part which he can never fully understand." - Friedrich Hayek