Yes. Reputations are easy, when you only have to do them on one character.
Yes. It's entirely optional, when the reputations themselves aren't endgame gated or offer anything rewarding.
Then, your argument has merit.
But when you have people who play countless alts, who want to be competitive at endgame, which, generally at the start of new expansions more or less requires you to max your standing with the newest faction, it's an absolute slog. It forces people into questing who might otherwise choose to level via other means, because now they have to quest to get the rep, because they can't just cheese it via tasks, or dailies with accelerators (I mean they still can, it will now just take twice as long, and it already took long enough doing it that way).
There is no realistic argument for their reason to remove these items. They have existed for as long as I can remember, and if they were not a problem then, they are not a problem now. They tried to get rid of them once before and there was significant uproar on the forums - like now - which resulted in them being made to Bound to Account - now, yet again they are trying to sneak through their removal on a days notice.
Talk about screw over your playerbase. They knew this would be an unpopular change hence why Cordovan hasn't been back online on the forums since posting the patch notes. They are fully aware their playerbase is going to drag them over the coals for this change.
Defend them if you want, but there is no reasonable argument for their removal.
In effect, all this does, is screw over their new playerbase anyway, because veterans most likely have upwards of hundreds of thousands to millions of marks, as their hasn't been a use for them (aside from reclamation scrolls) since the new LI system. So, I'm set, I went and bartered 5000 last night, I won't need any for a good while. I feel sorry for the newcomers though