How do you suppose this could be done?
Having a block maxed out with a lot more transactions is an incentive to the miners, as they will earn some more Bitcoins from the transaction fees on top of block rewards.
i guess if a miner had a large share of the network and they wanted to cause damage to it they could refuse to include transactions and just fill up blocks with whatever they wanted to, if anything. but as you point out, it wouldnt be in their financial best interest it doesn't seem like. but say they had 30% of the hash rate then i guess they could mine 30% of the blocks so they could slow down the network by 30% if they just mined empty blocks.
Miners cant afford that.
but large pools that do not share fees ie antpool can do it.
in fact they can do zero tx blocks slowing the network.
and not collect fees for others pointed to their pool
then point their own hash at viabtc as viabtc shares fees.
so they lose out on antpool blocks but whale on viabtc blocks.