Its part of EL AL history. First of all, EL AL had a principle that there was never a "row 1". Next, to cope with varying sizes of cabins, business class always started at row 9. Economy always started at 21.
I'm not that old but would assume on the 747 First class was on the upper lever rows till 8, so business started on row 9 across the board, econ always at row 21. Even the UP configuration started on row 21. Now that they don't have F anymore I guess they will renumber Business to row 1
There are many airlines like that, especially the Chinese. One always knows what rows are Business or Economy no matter the aircraft type