I'd much rather have underwater data centers. A floating data center seems like a massive eyesore and you'd need to run cables out there.

If you build one underground near the shore and then channel water in from the ocean, it should be much less intrusive.

Sure. A lot of that can be filtered out, but there will be corrosion with whatever heat transfer system they use. However, seawater is free, pretty consistently cool temperature (esp. in the Pacific), and is plentiful, so replacing some heat exchange components shouldn't be overly burdensome.

But that would require large capital investments that negatively impacts earnings reports.

Much better to screw over the people by taking their water for free.

Sure, but that means more space to allow for cooling the water so it can be reused. If you can cycle it w/ "unlimited" cool water from the ocean, it can be a lot more compact, and heated waste water could potentially be used by a desalinization plant to improve freshwater output.

Nuclear plants do that with lakes, they suck in cool water from one end and dump out the hot water at the other so that it can cool down by the time it circulates back in