It's not value destruction as long as the economy is growing with the money supply,
You can say it's not value destruction, but it's all least value transfer. My $1000 that I saved last year won't buy as much now as it would then. The value I have lost maybe now exists in the pocket of some government employee or central banker, so OK it wasn't destroyed. But I no longer control it.
Fiat (and Bitcoin) inflation devalues saver holdings to the benefit of the people who get the newly created money.
unless those sites grow their gambling base at the same rate as CLAM inflation, isn't inflation devaluing the coin?
No. It devalues each unit of the coin, but each (staking) holder gains units to compensate for that devaluation, resulting in 0% net value loss.
Perhaps CLAMs' ultimate weakness is its low utility. You just can't do much with it. Unless a (more robust) economy springs up around the coin, the current inflation rate is bound to devalue it relative to other currencies.
Suppose you have 100 CLAM and the price is 0.01 BTC per CLAM. You have 1 BTC worth of CLAM.
Suppose staking doubles your holding each year and halves the price each year.
By the end of the year, you'll have 200 CLAM and the price is 0.05 BTC per CLAM. You still have 1 BTC worth of CLAM.
You can cry that the price of CLAM in BTC has halved, but who cares? You still have 1 BTC worth of it, so it doesn't matter.
The only person complain is the guy who didn't bother staking for that year. He still has 100 CLAM, but now it's only worth 0.5 BTC. That's the incentive to stake.