Those of you on the struts-users list can skip the following--Copy&Paste rules.
1) How about this one from my RL experience...
I filled out a eBiz order form and mis-keyed my CC exp date. My transaction was rejected, and I was returned to the form... with nothing in it! I had to re-key everything. The Struts HTML tags take care of this problem for you, rather than having to trust that the browser will cache it or the user won't mind re-keying everything. HINT: If a user has to re-key something, they probably won't, resulting in lost business.
2) The key is that Struts helps you control the flow. You can skeleton out a whole app before it's even possible to write the business logic. I speak from experience here--I had a whole app laid out and assembled 6 months before the DBA's finished the schema for my data mart. I dropped in the logic, and voila, everything worked. Struts is *not* a business logic framework. It *is* a VC framework, waiting for your M. =) Trust me when I say once you learn it, it will save you time.
3) The key here is that Struts does everything for you that you'd have to write yourself.
If you want to write it yourself, feel free. Meanwhile, I've got a set of wheels and I'm off building apps. =)