Great piece you've written here! I'm sure many players ask themselves these questions about the game economics, and once you do some research it can become very complex very quickly, as there are so many factors that matter. In my opinion what we're mainly seeing here is just a factor called hype, which seems to be really common with almost any cryptocurrency. Even though this is a blockchain-based game, I've seen it with different card games countless times. A good example of it is Pokemon, at one point the cards are totally hyped, and Charizard doubles or triples in price. Next year prices decline and it halves in price, giving you a good investment option.
I just started playing Splinterlands but looking at how many prices dropped in the past few months, I would say now is the time to grab your "free meal" whilst everything is discounted. (please beware this is not financial advice).
Hopefully, this helps to fade away some of the negativity people feel about the prices going down. At least for me, I see it as an opportunity to hoard a new collection without the feeling of risking too much.
I am also continuing to add cards. I think the decline in Hive also pushes down DEC, but I think also, that DEC is being driven down to 0.001, so that SPS can become the preferred currency for Splinterlands. We'll see, over all I am bullish even though we seem to be fighting a bear at the moment.