I don’t disagree with your line of thinking but he was a 6th round pick. Not sure why it’s considered a wasted draft pick since majority of 6th rounders don’t make the NHL.
Most 6th rounders are still at least somewhat promising. Rindell is a pure offensive defenseman with below average skating ability and even worse defensive ability... And his production has only gone down since we've drafted him. Look at the other 6th rounders we got from that draft: Veeti Miettinen was really good last year and while he was not as impressive this year, he is still a guy who can legitimately be seen as a top 15 prospect in our system. Joe Miller had a tough time last year, but is one of the top guys in the USHL this year. Neither are really "top notch" prospects, but they are significantly more promising than Rindell has ever been. Or look at Ryan Tverberg, who we got in the 7th in that same draft. Devin Levi was taken right before Tverberg. Rory Kerins is 2nd in OHL scoring as a 6th rounder from that draft. Ronan Seeley is a nice defensive prospect taken in the 7th of that draft. I had Kerins, Miettinen, and Seeley as top 125 picks in 2020.
Most 6th rounders don't turn out, but it is not an excuse to make poor selections either... And Rindell was a poor selection from the beginning. From day 1, he would only crack an NHL lineup as a heavily sheltered bottom pairing PP specialist, and those don't really exist anymore. So what was the plan for him? Turn him into something completely different on top of completely overhauling his skating?
Now in terms of the Marlies and the contract he just received, what is his role? He is not good enough to be an every day guy right now, and we don't exactly need more depth guys when we already have 3 AHL contracts + Villeneuve + the Growlers captain to fill 3 ECHL roles and 2 Marlies depth roles. Now, if we plan on using him at defense, we have to put Hollowell as a top 4 RD and Villeneuve as an every day guy on Day 1. Neither of those things are ideal, especially just to fit another pure OFD in the lineup. We will have all of the downsides we currently face with our current Marlies defense with Duszak in it, except Duszak is a PPG defenseman, a much better skater, and at least is decent in his own end.
Now we could move Rindell to forward, which he has played at times in the past in the Liiga, but just like Duszak, he doesn't exactly have qualities which would make him thrive as a forward either... Especially with his skating ability.
Right now, I am thinking we are looking at a RD version of Noel Hoefenmayer... and I am not even lining up to give Hoefenmayer another AHL contract, never mind an ELC.