Unreasonably large spreadsheets are surprisingly common. Excel 2007's row limit was 65536, and nowadays it's over a million. Spreadsheets actually get that big, too.
An app I worked on once wanted a Google Sheets Integration - just a quick button to import rows from the database and into the spreadsheet so that the client can do some quick visualization and pie charts (I offered them a readonly DB account but they didn't know any SQL).
Few years have passed, and there are currently 470 THOUSAND rows with 20+ columns in that spreadsheet which is used almost daily.
Rewriting this into a proper web app would take maybe a week (the API is already there and used by GS), but was never deemed a priority, so it will keep existing in the backlog until we hit row or cell limits - after which it will suddenly become urgent...
Did the commenter say that it was being edited concurrently? Because that's the only circumstance in which it would really be acceptable for it to break like that.
which is an awful idea because some versions of Excel will, if you open a file with more than 1million rows (or ~16k columns), automatically truncate and delete the excess data! And don't even get me started on automatic date conversion.
