Coins can be mined out of existence (miner selects a reward less than the max allowed).
I wouldn't call that destroying them. Yes, it causes there to be that many fewer bitcoins in existence, effectively accomplishing the same thing as destroying them, but if the address created by the miner has less than the current block reward, the coins never existed, and therefore weren't destroyed.
Imagine a miner mines a block full of transactions, and those transactions paid a total of 3.5 BTC in transaction fees.
Imagine that miner sets his block reward to 25 BTC (instead of 28.5 BTC).
Couldn't you say that the 25 BTC block subsidy was created, and that 3.5 BTC in fees were mined out of existence?
The coins did exist. They were used as transaction fees. They were destroyed.
Starting from 0.9.0 transactions with a single OP_RETURN have become isStandard (so will be relayed). If you really need to destroy coins use those, as they are provably unspendable (unlike funny eater addresses) they do not burden the UTXO set forever.
How do you get more provably unspendable than an address that can't be generated?
How do you prove that an address can't be generated?