When you say "swim platform", what style do you have? There are many styles out there. If I took a guess, though... do you have the small, white, plastic square style with a stainless grabrail from it to the transom on one side of the platform? Is the ladder currently attached to the top of the platform or bottom? Assuming... top?
Assuming all of the above... It's pretty common for those to creak, moan and squeal when someone uses it. But they're not as fragile as it would sound. However, you could very simply make it stronger. A piece of aluminum, SS or even fiberglass angle iron attached under the platform from port to starboard (near the back edge), and then another support bar run from the angle iron, down to the transom. This could be done as simply as crushing the ends of a SS tube and then bending them to the appropriate angle.
Personally, I don't have any experience with a folding platform. But are you asking because of the water spray issue? Maybe this is common to your hull, I can't answer that. BUT, "typically" when a boat is squatting it can be rectified with a combination of engine down trim and the use of the trim tabs, possibly fully deployed. It will also level out the boat and bring the bow down for better forward visibility and a smoother ride.
