Actually this doesn't surprise me. I study business logistics and this is one of the thinks I learn about, Make or Buy decisions. The scampi is not a high quality product in which you can taste the difference between fresh and frozen. Frozen they remain well for years, so time is not a problem. Sea transport is extremely cheap (a boat might be expensive, but you haul a lot of cargo), and so is labor in Thailand.
A good example of globalism
For once you have tasted flight you will walk the earth with your eyes turned skywards, for there you have been and ther