I really don't know what everyone's obsession is with getting every job they play to BiS as quick as humanly possible.
I also don't get when people think it's a flaw with the game that it takes a long time to do.
To put it simply, the fact that you don't know whether you'll get that one piece of gear this week makes the gearing more satisfying. This is a tried and tested method for MMOs that's been around since the genre's inception.
Furthermore, Best in Slot is only a requirement for new Ultimates, which release months after the savage patch, and remain relevant forever. As people have mentioned, there are Ultimate prog and clear groups up on PF round the clock for all five fights. I promise you, you won't have any issue getting a FRU group on your fourth class if you get to it an extra month or two down the line.
If you're only going to be doing Savage, then you just need to craft or buy your 710 gear, or do normal raids for tokens if you don't mind the waiting, and you're set. We all did the tier week 1 with that ilvl. If you can't manage with 710, then 730 won't help you much.
Essentially, Best in Slot is an achievement. And we as gamers tend to look down upon those who ask for achievements to be made easier for any reason.
"I need BiS for parsing" says the strawman. To whom I reply: That's not officially supported, and unless you're using a stopwatch for how fast the boss dies, or reading through a long battle log with a calculator, you need to break ToS to do it. Wouldn't recommend.
"Why shouldn't I be able to clear an Ultimate week 1 with seven different jobs" says the strawman. I respond with a question of my own. Why should the loot system be upended entirely for the relatively microscopic percentage of the playerbase who clear Ultimates in multiple jobs when they're current content? It's nearly impossible to tell how many people try each fight, but best data I've been able to find says that less than 1% of players cleared TOP. Not an insignificant number of players by any stretch, but certainly paling in comparison to the average PF savage raider.
And again, you have months of time to gear up your favorites. Maybe not all of them, but that's when you have to pick and choose. That's not a bad thing to specialize a bit. We're all Warriors of Light, but everyone's a bit different. If we're talking about this for the benefit on the player who only bothers to log in right when the Ultimate Patch drops, then I'd first question their foresight and how much they truly know about Ultimates. Next I'd question how many people this truly accounts for, and again, Is it worth upending the whole loot system for?