If we are hoping that Apple will read this and take note, I would like to add emphasis to the part about copying the value in one cell and pasting it into a range of cells. It can't be done. You must paste and click and paste and click and paste and click and paste and click and paste and click and .....
Likewise, the Edit->Fill command doesn't seem to exist.
Let's say you have a series of numbers in column B and you want to put the word Detroit beside some of them in column A, Chicago beside others, and Cleveland beside others, so that your next step would be to sort by city and produce substotals, for example. Where contiguous cells exist with the same desired value, you ought to be able to select the range and paste. With any date or number-sensitive cell, you get arithmetic progressions, which is handy when you want it but not when you don't.
Or let's say you simply want to fill all of column A, or a range within column A with something that is not a progressive value. Can't do it.