What did the approved finish samples you signed off on show color wise? Did he even make you a mockup of the finish? Tough to tell on a computer monitor but not all pieces of wood will take the stain exactly the same way,

Your finisher is a hack.

I have to agree I am pretty sure this could have been better but what did you sign off on that is really the issue . You needed to see a sample in the wood you were using at this time and I also agree taht wood does notall take staint the same and especailly a wood with a lot of grain but this is bad.

Alder is prone to blotching when stained. (Pine and especially maple are also difficult to stain.) Best to stick to lighter stain colors than a dark one like the OP's. Along with using blotch control treatment prior to staining and even toners. Toners are essentially tinted clear finish. Downside of toners is that toners will hide the grain of the wood.

I agree that the cabinets suffered in the hands of a less than qualified finisher. Building & finishing are two separate art forms.