Is it going to take more than two days?
Is it going to take more than two weeks?
Is it going to take more than two months?
Is it going to take more than two years?
If you can answer these questions, you can estimate using a confidence interval.
If the estimate is too wide, break it down into smaller chunks, and re-estimate.
If you can't break it down further, decide whether it's worth spending time to gather information needed to narrow the estimate or break it down. If not, scrap the project.
I prefer it over estimating which feels more like asking the length of a piece of string.
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.
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.