Online Review of Manuscripts: More haste, less speed?

With the modern culture of online submission and review systems, are peer reviewers being exploited and undervalued? What was once a simple process of accepting to review a paper, receiving it in the mail, and, eventually, returning it to the editor now requires passwords, usernames, printing off a hard copy, electronic reminders, and, tediously, entering all review comments electronically. Why not just say no? The hard work of the review process should be judging the paper, not fighting the program.