It's grammatically correct, but it has lost a piece of information: "reality":
It must be said that reality has whatever qualities are claimed for it.
And now it has subtly changed its meaning, because "it must be said" is a standard way of saying: "I now feel obliged to make a concession in my argument".
Conclusion: leave the original sentence alone. It is so vague that altering it is like trying to move a spider's web. If you want us to say more, give us the source and more context.