This is not just a Belmont trend, this is an industry trend. The lone exception is a one-year expcetion, and that's Monmouth (but they're not all allowance races either).
We are right in the middle of a changing shift in the overall quality of horse flesh this sport is producing.
Quantity (at the expense of quality) is becoming a big problem, especially when you consider breeder awards etc.
It makes more sense to breed 10 mares to a $2,000 stud than one mare to a $20,000 stud. The 10 mares, when factoring in rewards, have a greater chance of positive return than the one.
This weekend I'll see horses run for more money as Louisiana-breds than non-La-breds which are running for less but are likely faster.
The result of all this is cheaper races, which we have to get used to for the time being, from the top to the bottom.