Jodie,
Its a common mistake to think pictures and/or footage would be of no help. IMHO, its just another footer excuse for not having reliable evidence.
The use of images is a routine in science. In doubt? Google for Hubble Space Telescope. What's the difference between the images used by science and those used by footers? Sharpness? No. The first Hubble images were quite blurry but scientists studied them. So, where lies the difference?
Provenance, reliability, reproductibility.
No bigfoot image presented to date can be trusted, due to the image quality itself (ex. blobsquatches) and/or to issues related to provenance (ex. PGF, Melissa's picture, etc). The images sold by footers do not pass basic QA/QC tests, so they are useless when it comes down even to trigger any serious investigation effort.
Note that the people who claim multiple encounters ("habituation") with bigfoots should be able to provide multiple images, pictures and footage taken at different days. Where they are? Hey, you've got bigfoots at your backyard! Why the professional photographers from National Geographic can not capture them on digital media, video tapes or film?