I don't agree with this.
The Collison/Gay/Cousins trio last year played much better together than the Rondo/Gay/Cousins trio, so in a sense, losing Rondo actually makes us better. Rondo/Gay/Cousins w/o any other PG on the floor was +0.8 last year whereas the prior year Collison/Gay/Cousins w/o any other PG on the floor was +13.5. The "w/o any other PG" element is interesting considering Karl decided to play two PGs (Rondo/Collison) on the same floor a good chunk of the time which really hurt us (-3.1 when they were on the floor together).
Now this year, we're back to the Collison/Gay/Cousins trio without another PG who is going to force us to play a weak, two PG lineup for many minutes each game. That right there should make us better immediately. Factor in a healthy and in shape Cousins (which he is), an upgrade at SG in Afflalo (still great or elite but he's better than what we've had), some defensive/shooting roleplayers and our team should be better equipped this season.
It's an easy and lazy approach to look at the Kings last year and say they won 33 games and didn't add anyone useful therefore they will be right around 33 wins again. But anyone who understands the NBA and how it works knows there is much more that goes into it. Schemes, buy-in to what the coach is preaching, chemistry, fit, style of play, etc. You seem to be focusing on one aspect (talent acquisition) and that's what leaves your argument vulnerable.
Many of us believe we had the talent to compete last year and that Karl royally screwed things up with his rotations, schemes, style of play, alienating his best player, etc. but of course, none of that gets factored into the equation for the general NBA fan because it's complicated and too hard to quantify. Instead, people choose to ignore it and focus solely on the record last year and who they've added this year.
You're missing many pieces to the puzzle, my friend.