File compression

The readme rightly states:

> Files encrypted with git-crypt are not compressible. Even the smallest change to an encrypted file requires git to store the entire changed file, instead of just a delta.

However it seems to be a relative simple feature to allow git-crypt itself to compress (large text) files before encryption, and decompress them after decryption.

Was this considered and if so, what are the gotchas that prevented implementation?