If someone wants to make a point, make it. But just making a smartass comment or a wisecrack is not contributing to the discussion whatsoever.
That 1RM calculator can only give estimates based on the "average" person with "average" endurance. Someone who is very very lean (like I used to be) may be able to do more reps of a certain weight than the average person, yet do less MAX weight (1RM) than the average person.
If a person's weightlifting routine is all about high reps/low weight, they'll probably be able to do a lot of reps, but their all out strength for 1 rep will be lower. On the other hand, a power lifter whose routine is very high weight, very low reps will be able to do a lot of weight on 1 rep, but their muscle will probably not be lean enough to do many reps of a lower weight.
Not everyone is "average", some people optimize for endurance, others optimize for all out power, explosive strength. Such a formula doesn't take into account what kind of muscle you have.