This is largely true. English takes '-ard' from Old French. MW defines it as:

one that is characterized by performing some action, possessing some quality, or being associated with some thing especially conspicuously or excessively

The main point is that it's generally just a pejorative suffix.

Citing the Trésor de la langue française informatisé, however, Wiktionary puts forward a surprisingly cogent counterargument and alternative etymology to the "packsaddle" one for "bastard".