This is no different than Wampa, ROLO, or Hoda being needed for JML. The game is all about time. You can spend money to shorten the time it takes to accomplish goals, or you can change your play experience to reach your goals, but there's nothing instant here.
And if your guild mates really want JMK, then they should farm and gear Geos for the Wat mission. If only 8 of you want JMK, then there are other choices to be made. I know of a 145M guild currently getting 23 Wat shards. They don't mandate geos either; that's just the decision their players made because they knew Wat was a good toon and Geos are a great starting fleet. There are plenty of good guilds that aren't going to hinder your progress.