I might be mistaken, but I believe sneak was referring to the general irony of using RSA, whose underlying strength relies on the math problem of large number p

I might be mistaken, but I believe sneak was referring to the general irony of using RSA, whose underlying strength relies on the math problem of large number prime factorization, as a deterrent to keep out calculator enthusiasts, who presumably would find such a problem interesting. (Rather than the suitability of the key length of 512-bit RSA, which as you pointed out, was good enough back then) However, I guess the same could be said for RSA being used in any product used by technically-oriented folks.