I prefer it over estimating which feels more like asking the length of a piece of string.
When I’m asked on longer time frames, I’m much less confident but it’s still more concrete than the other way around.
I hope this is tongue in cheek, right? If not, here are some reasons:
1) spreadsheets embed "functions" via macros and macros are often flagged as malicious. Just combining native functions can get pretty complex.
2) in a spreadsheet, everybody sees the input, which is not always ideal
3) data types are controlled by users for the entire column or sheet, which can mess up formulas
I could probably think of additional reasons.
How do you know if your estimate is good? Would you rather bet on your estimate or on hitting one of 8 numbers on a 10-number roulette wheel? If you prefer one of the bets, adjust your estimates. If you're indifferent between the bets, the estimates accurately reflect your beliefs.
(The roulette wheel is from the book, How to Measure Anything by Hubbard. Confidence interval estimates are from LiquidPlanner, https://web.archive.org/web/20120508001704/http://www.liquid...)
There also are people who use software to guide space rockets, cars, optimise calculation algorithms and more.
My guess is people with background mostly in CRUD don't get how everybody else messes up estimating so badly and people in the innovative task group find it hard to believe sane people would waste their time giving any estimates other than for technically irrelevant business reasons.