Blackboard (the webapp) itself isn't that bad, and the iPad app is really nice. It's just any site that tells you that you just failed a quiz is bad by association.
I can name a few problems with Blackboard (the webapp). I've seen both sides of it; I've suffered through 7 semesters with BB as a student, and 2 as a teaching assistant.
It uses frames. When you open a link in a new tab, you get the bare page without the top/left nav bars. Really? They couldn't even use a little 1998 Javascript to get the page to reload inside the frameset?
Too many modules are enabled by default, which causes confusion when profs use things differently. Does the syllabus go in "Course Information" or "Course Documents"? Or, since it contains the prof's email, "Staff Information"? Do homework assignments go under "Assignments" or "Course Documents"?
There are two ways to upload files. One is convenient for both students and teachers, one is not. Guess which one is more obvious? The nonintuitive one, Digital Dropbox, is buried two pages deep. It has two choices: "Add File" and "Send File". If you add a file, but don't send it, the teacher never sees it. From the teacher's end, Digital Dropbox renames files, for your convenience. Yes, BB, thanks so much for renaming my students' Java files so that I can't compile them. Also, for your convenience, any .html files that are uploaded get their extension changed to .rtf, prompting more shell scripts just to de-BlackBoard your students' files.
The better upload option is for teachers to allow submissions in the Assignments tab. This makes way more sense, since you can view and complete the assignment all on one page. To enable this, the teacher has to select an assignment type of "Assignment", instead of the default "Content Unit". As a TA, I only knew this existed because one semester, one of my profs used this. (Once, out of all the classes I took that had digital submission.)
The grading page is horrible. It has a table for the grades, like you would expect, with one column per assignment, and one row per student. If you have more than 5ish assignments or 15 students, it overflows the page. This would be fine, except the table doesn't respond to the scroll wheel. It has a scrollbar on the right, and a scrollbar on the bottom, and watches their position with Javascript. When you scroll one of these, the table contents are updated to reflect that position of the table. This makes scrolling awkward every time - the screen flashes a bit, and you have no idea how many columns Blackboard decided you wanted to scroll until you look at the header row. Oh, and every time you resize the page, the table is reset to the top-left.
TL;DR These people need some serious UX help, fast.
The better upload option is for teachers to allow submissions in the Assignments tab.
Is there a way to quickly download all submissions for an assignment at once? So far, I've been stuck with going into each submission's sub-page and clicking the download link.
The grading page is horrible. …
Also, columns you tell it not to use in grade calculation may simply not appear anywhere.