The community of players may not be so big at the moment. But I don't think they designed a game 17 years ago thinking they weren't going to grow to be big! In addition, the number of times actions are performed and decays are generated over time for just one player could be immense (multiple weapons, tools, armor, clothing, vehicles, etc.).
Also look only at the accounts in this forum over time and there are 56 thousand. (And we all know that not everyone enters to this forum and that such a number could represent only a small fraction of total players over time.)
Really, I don't think Mindark lied to us on this matter. Simply that MA has not been able to determine it as they have stated.
Rather, I think they should rush to compensate the afected Mayhem players just as they said, in case they haven't already.