That's because it isn't cheap for them to get the private keys. That address might be in cold storage, for example. When they get the private key for that address they will expose the whole cold wallet and they will have to move all their coins (probably millions of dollars). There are many risks (like missing coins, messing seeds backups etc), costs (like mining fees and developers` time)
They don't need to expose their cold wallet nor create a new one. They can craft a Doge transaction sending the coins back to OP and sign in the cold wallet. If signing a tx was that hard, they wouldn't even be able to move their BTC when they need to. The problem is that this probably has to be done manually, and by someone with access to the wallet, so its time consuming.