"Did somebody paint a big bullseye on Island Packet sailboats or what?"
Yes, Island Packet did when they chose the design approach that they did. Its simply a physics thing; huge amounts of wetted surface, a poorly shaped underbody, and foils, a dearth of sail area and an excessively inefficient rig proportion.
That is not hearsay, its just plain basic physics. And it is easy to quantify the relative impact of that design approach. When you look at the PHRF rating in any Region with light to moderate prevailing winds, the Island Packets are typically 60 to 90 seconds a mile slower than boats of an equal length, and 2 to 3 minutes a mile slower than more normal designs of an equal displacement. Those kind of number are huge difference in speed, and in cruising modes, slower boats generally do worse than their ratings might suggest. PHRF normally spots cruising boats a little time in racing mode, and so while these numbers may do Island Packet a 9-12 second disservice in racing mode but they clearly show that Island Packets are a bit doggie.
And that matches what most of us have observed out there on the water. In reality, my observations sailing IP's and observing 100's of them under sail for decades is that they really do not perform at the low end of the wind range.
While you may be able to crowd a large enough genoa on a Island Packet to close-reach at "3 knots in 5 knots" of true wind, that would result in an apparent wind of somewhere around 7 knots. In the same conditions a decent light air boat, i.e. one that is not a little doggie, without an oversized genoa, would be generating closer to 8 or 9 knots apparent wind in those same conditions and would be moving closer to 5 knots through the water, in other words doing close to the true wind speeds. And that is the precisely the point being made when people say, Island Packets are a little doggie in light air. But not only are they slow in light air, but they also make gobs of leeway compared to boats with more efficient keels.
In the end, what counts is you are satisfied with the performance of your boat, and that is a good thing for you. As such it should not matter to you when other speak of the relative capabilities of the IP's.
But when someone asks for a relative description of the performance of these boats and thier suitability for use in a predominantly light air venue, the alleged offshore capabilities of an Island Packet (I say 'alleged' since the A Offshore rating really does not really define the suitability of a boat for offshore use, just its likelihood of surviving out there) may be relevant for some, offshore characteristics were not the question being asked. What is relevant, is the observable light air performance, and IP's poor light air performance is easily observable by anyone who has sailed one in light air or seen them try to sail in light air.
Jeff