The vast majority of users within our organization that utilize Workfront are not Project Managers and have little to no experience with project management tools but are looking for an easy alternative to Excel. As such, we don't expect these "non-technical" resources to dig into the differences between all of the available task constraint options or create flowing, linked task lists in which options like "As Soon as Possible" would apply. We always direct these users to change their task constraints to "Fixed Dates" when creating new tasks in order to have full control over "planned start" and "planned completion dates" of their tasks. This further complicates the process for already overwhelmed newcomers to the tool, and is the cause of a lot of strife for onboarding new teams.
A great solution for this would be to create a settings option within "Setup -> Project Preferences -> Tasks & Issues" in which a system admin could set the default value system wide for the "Task Constraint" field.
