There certainly are engine swaps that indeed RUIN a good car. But like anything else, there are the good, the bad and the ugly.
I have seen a number of engine swaps. I have certainly seen some butcher jobs that did indeed ruin a good car. I have also seen some that looked factory. I have seen the pictures of Richards job, the pictures coupled with the fact that he has driven this car for two years with no trouble tells me that this was a first rate job and did not ruin his car.
It's all in the quality of the work.
Have a great day,