I think a lot of people like the idea of staying on a firmware like 5.05 - 7.55 purely because they believe a permanent exploit could come out that only works on older firmwares.
As for backporting, it's likely we'll still need a method of backporting games for use on FW9.00 when games that rely on newer firmwares are released. Does anyone have a link to a guide or method of backporting games for yourself?
I've also asked this before, but is there any danger in installing a backported game/ update (For example, FFVII Remake backported for use on 5.05) on a 9.00 console? I can't see any danger, but Godreborn mentioned that it isn't recommended and I'm just looking for some reasons why!