Who are the good teams that are signing their position players to long term, high dollar contracts into their mid thirties? Not signing Harper and Rendon is all about not wanting to hamstring the baseball team 4-5 years from now, and the LAC arguments seem way off base.
It's not really a LAC argument. I do think the team, at least since the RZ contract, will not sign one of their own developed guys early unless he signs at a discount to market. I think Stras is the exceptional signing that proves the rule, especially if he opts out. It's saved their butt with Desmond and with Zimmermann, and probably will end up a good move with Harper, too. Would I rather they take some risk and lock down a Soto or a Robles (ship sailed on Turner) while they still had some pre-arb years left and use that risk to buy a couple of cheaper FA years? Yes, but I realize it takes players willing to do that trade off too. That said, if it were a coin flip, you'd think occasionally the coin would come up heads and we'd sign a few of these guys early.
However, I said this isn't a LAC argument. What I think the argument is is that baseball fans are not day traders, indifferent to the inventory being held at any time. If you want some emotional investment from fans, players they've seen develop and whose jerseys they've bought need to be retained occasionally when it makes sense to the team structure and the market. Arenado is probably worth more to the Rockies than Rendon would be, no matter how similar they are statistically, because the Rockies fans have invested in Arenado. Similarly, Donaldson on a 1 year deal might be worth close enough to Rendon to make some sense on the field as a short term patch, especially if Kieboom walks on water, but it will chafe on the "fan" and the loyalty aspect around here. The countdown to Turner's departure is next, after Rendon leaves and Strasburg opts out. Why bother to buy a season ticket or a jersey?