“I still can’t get over rebdoniel’s assertion that the fact that a hechsher stays in business proves that it’s reliable.”
It may not prove its reliability, but is certainly proves that someone believes it brings value to the product it is on.
Sadly, the saying, there is too much Kash in Kashrus, leaves a dark cloud over kashrus in general.
Many companies use a kashrus symbol as a marketing tool, as some believe it symbolizes some level of quality and purity. It is why products that need no hechsher at all, such as plain bottles water, or, for those who drink non chalav yisroel milk, plain milk have a hechsher on it. It isnt there for any kashrus purpose, but, since the company has a contract with a certifying agency, and, these products are “kosher” the symbol is added anyway because from a marketing standpoint it implies purity.