Students will often do their pre-class work by hand (especially if it involves math or plots) but then have no way to paste it into the poll. Asking them to upload a photo of their work as a resource to the class can be confusing if they don't put their name on it. Plus, this leads to professors needing to dig through multiple avenues (the poll, the chat, the class resources, email, etc) to find the students' submissions.
