Use a bit of logic.
If miners would want just bigger fees, why would they release a coin that has less fees?
If they would want bigger fees, wouldn't they have launched a coin with 100kb blocks?
The debate was about what big blocks will lead to and now nobody would be able to host nodes at home with 1GB blocks coming every 10 minutes.
As for the spam they are just trying to make people shift to their altcoin, the fees are still negligible compared to the block reward.
Not forgetting that they are losing money with this spam, as some of the that get confirmed are their own.