One of the major considerations for LP providers is Impermanent Loss (IL) when the balance of tokens becomes skewed. Let's consider Hive/SPS. When hive spiked in price over the last couple days while SPS remained relatively stationary, aside from ranging between say .44 to .58, the massive price fluctuation in Hive would have created a significant amount of IL if one were to remove their LP to say, cash in some Hive during the pump.

The nice thing about Dec/SPS is that the price of assets is directly correlated, and tends to move in relative unison. Because DEC leads directly to daily airdrops in SPS if one asset moves the other is likely to move in a similar direction. This price correlation reduces risk from IL. As other comments mentioned, providing the LP doubles Dec airdrop points for the amount of DEC staked in the pool.

Their price is so closely related it's may be better in many cases that providing LP on a volatile asset paired with a stable coin.

Hope this helps.