The issues with the current state
First off I want to adress the issues that we currently face with the class system as it is today, so that we're all on the same page regarding the development team's response towards them. For starters we have the process of levelling other classes to high levels in order to unlock essential cross-class skills. This can be a tedious process for most players, and this is something that I myself agree with 100%. Levelling a Lancer to 34 just to unlock Blood for Blood almost feels like a waste of time, which is why the development team have decided to remove this process entirely. But what if I could learn Blood for Blood from Lancer before level 15? And on that topic, what if I could learn all necessary cross-class abilities from all classes before they hit level 15? The solution to this problem is to reduce the level requirement for necessary cross-class skills - not that they should be removed from the game. You wouldn't amputate your leg just because it's broken.