Why does GPG require you use redirection to handle large archives?

A problem a lot of people have run into with GPG is that if you try to decrypt a large archive with, e.g., gpg --decrypt archive.gz.gpg > archive.gz you may receive an error such as

gpg: fatal: zlib inflate problem: invalid block type 
secmem usage: 1920/3872 bytes 

For example, see this short mailing list correspondence. As you can also see from this correspondence, the solution seems to be to use shell redirection: gpg --decrypt < archive.gz.gpg > archive.gz.

I'd like to know why this solution works and the underlying problem it is a solution to. Verbosity in answers and links to exteal resources would be much appreciated.