Because they were called different names in essentials IIRC?If you start making significant changes to how classes in the PH work, you have crossed that line IMO. This is why Essentials wasn't an edition change, but rather a big supplement or a new corebook to play from, depending on your perspective.
I mean they could do the same thing here, not that I think we will.
I can see that, it doesn’t personally bother me, but that makes some sense. If I can’t use them at the same table I can see that being an issue. However, from what I have seen o think I will be fine in that regard, similar to how essentials worked with 4e