And almost no one will have to. As I said, most linkshells will easily finish within a few months (that's most linkshells that even own relics, many linkshells still have none, but this isn't about them). And they don't even have to, that's only if they want to get all their weapons upgraded to the top right away. And again, this is the final weapon (not counting glowing one, but that's another issue altogether, as it will never be obtained at all at the current rate). Unless they introduce yet another form of ultimate weapon in the new content, they will have the maxed out weapon in a few months of very casual effort (to most people who own relics, 2h a day is hardly effort at all). This is clearly targeted at the players who were willing to invest in a relic in the first place, which are usually people who don't mind investing a lot of time in upgrades for their gear.
I agree it's not perfect, but I honestly doubt we're gonna get much better than this. At least this isn't unreasonable anymore.