Honestly, getting a class to 36 should take you less than 12 hrs game time (it is possible to get 50 in less than 24 hrs game time). And since you have a friend who is 50 you guys can powerlevel each other.
Plus (for now) sentinel is a great ability you will use time and time again especially for other end game content.
Also a note on Ifrit, it was designed to give hardcore players a challenge. These are players who play 8+ hours a day. Players who have all their classes at 50 and the resources to power up their gear with expensive materia, not the run of the mill casual player with one level 50 class. Unfortunately for casual players if they didn't have something challenging to do this game would surely die off.
With XP so easy to earn at the moment I believe the developers expect players to have multiple classes at 50 to clear the current end game content.
I think this is a great system. When the game was released it took 3-6 months to get a class to 50. If that were still the case then, yes, I would complain that needing multiple jobs at 50 to do any content is unfair. But now that you can get a class from 1 to 50 in three days I think it is totally fine to expect players have multiple classes at 50.
Casual players can get one class to 50 and feel like they are high level and hardcore players can get all their classes to 50 then they have crafting and gathering. Everyone is happy. I actually think it is too easy to complete a class. I consider myself a casual gamer who started at launch and I have 5 out of 7 classes done.
If you expect to complete the hardcore content when it is new, then you will have to invest as much time as hardcore players invest. If you don't want to invest that much time, then wait and settle for beating it when the developers make it easier. Maybe one day Ifrit will be solo-able ^^.
Despite this, I do feel your frustration. And wish there was something fun that 2 players at level 50 can do together. I play with my best friend also and without a party of 8 there is really nothing exciting to do.
Please Developers of Final Fantasy XIV design some content for two level 50 character to do together and save this game!