Legacy data may be the key factor Copying data has become a knee-jerk reaction to situations that require more than screen scraping. A limited amount of data. Relatively stable data. You need to have few or infrequent updates to the copied data. A large initial data migration is okay if the ongoing data migration effort will be manageable.
Old data has to be acceptable.
Be sure to match the business requirement with practical data synchronization capabilities. In general, you'll get more headroom by taking the remote objects coding approach. Data that remains viable on the mainframe means that companies don't have to purchase new servers to store the information. It means that valuable time won't be lost migrating the data to a new platform. Nor will you need to deal with ongoing synchronization processes and the errors they create.