While I agree with you on most of the issues, the SPS delegation is consistent with how it was planned long ago... You can see the SPS proposal here

From Splinterlands, July 2023:

It is important to note that in order to stake SPS to Soulkeep to increase the reward shares multiplier in the game, players will need to delegate staked SPS that they own in their Splinterlands account to a special $SOULKEEP system account. This will be able to be easily done through the SPS management page in the Splinterlands game website.

When SPS is delegated to Soulkeep (like with all delegated SPS) it will no longer count towards your SPS staked for Splinterlands ranked battle rewards. This means that players who would like to earn rewards in both Soulkeep and Splinterlands battles will need to have enough staked SPS to achieve their desired multiplier level in both games. It is also important to note that SPS cannot be "re-delegated", meaning in order to use SPS for Soulkeep, players must own that SPS in their account and cannot rent it from other players. We will look into ways to allow renting SPS for Soulkeep in the future.