Considering that all standardization work is performed not by ISO itself, but by national standard bodies (often funded by tax payers), I don't buy this argument.
It is true that sales of publications is a major source of income - 30% according to the ISO website - but what is that money spent on?
ISO is in itself just the ISO Central Secretariat in Geneva. The secretariat:
- has 154 full-time employees
- costs USD 40 million a year to run
For a purely coordinating role, 154 employees seems pretty excessive, and so does the yearly expenses at USD 257.056 per employee. USD 40 million a year, and then you haven't even produced any standards yet!
To get any work done, you need to add an estimated USD 140 million a year spent by the national standard bodies on ISO work, and an unknown (but probably much higher) amount spent by the participating companies. And none of this is paid for by selling ISO standards!