Because the results were probably wrong because the inputs were wrong (exagerated by over-cautious users). There is no automated way to avoid that in a calculator; only a conversation with a real person (sales, tech support) will reveal the bad inputs.
I wonder if some of that could have been automated. Have a field to indicate if you are an individual, small business, or large business, and then at least flag fields that seem unusually high (or low, don’t want to provide too-rosy estimates) for that part of the market.
