Waste of everyone's time if there's no realistic reason to pick a guy. At the end of the day we do generally bring in a handful of trialists every preseason. If we really wanted to, we could invite an undrafted player. But at that point you're better off bringing in USL players who bring more to the table than a guy that falls to 4th round.
Extra body that you have to pay extra expenses for (travel, food, insurance, hotel). No sense drafting someone if you don't have some intention of signing them. Rimstad was local, which is my best guess for why they drafted him instead of passing.