Why would someone store text in an SQL Image field?
The only options to store data over 8000 bytes was text, ntext, or image back in the days of SQL Server 2000. The appropriate choice for long character data strings would be text or ntext, with text appropriate for single-byte characters tied to the column collations code page and ntext for Unicode (UCS-2).

I can only speculate as the why developers used the binary image type to store character data but it could be in order to store characters as UTF-8, which is more compact that ntext UCS-2. Although this method saves space, it does come with the cost of not being able to easily evaluate the character data in T-SQL; encoding/decoding of UTF-8 stored as binary needs would need to be done in the application code.