For a long, long time I agreed with you. However, due much in part to the urging of people here I went to H rated tires on my car when I bought the Primacys. There is no handling difference. Going one speed rating down isn't the end of the world. I would tell you never to put S or T rated tires on the car...but to go from a V to an H rated tire isn't an issue. Much of the construction of an H rated and V rated tire are exactly the same...its not like looking at an S rated tire and a V rated tire.
Don't trust tire shops automatically. I've had tire shops tell me and do some crazy things over the years like mount directional tires backwards, use clip on weights under trim rings so they stick out...crazy stuff.
For instance the LS430 came with tires with an H rating from the factory when the LS400 always shipped with a V rating, and its heavier and higher powered than the ES. The Camry also comes with S rated tires in some trim levels and much of the suspension is the same as on the ES. Even if it weren't...the suspension is the same on all models of the Camry...so how can some have S rated tires and some have V rated tires?
I absolutely would not pay $50 more per tire to by the Energy S8 which is a crappy tire with poor treadwear, no treadwear warranty, and poor survey results when I could buy the Primacy which is a MUCH better tire. I've run the H rated Primacy on my ES which shipped with V rated tires for 40,000 miles with zero issues whatsoever. The Primacy comes in a V rating in my size...but I'll replace mine with another set of Hs.
Google and find a case of an accident that happened because tires of a lower speed rating were installed on a car...there aren't any.