I wouldn't consider it acceptable. I've been doing woodworking for 50+ years and have no idea how they messed that up. Besides the cracking, there seem to some other cosmetic defects in your photos.

Alder has knots, and splits and quirky grain at it’s best to begin with. It is blotchy and murky when stained as well. Alder is also very sensitive to moisture, and naturally moves around a lot, even in a veneer. It isn’t going to be it’s best in a damp wine cellar, or look that great from the beginning. This is a poor material choice, as well as being a poor quality material being used.

Color matched Sharpie and the cracks will disappear.

You might want to read this article to give you a good base when you have a conversation with your carpenter. This is part of one sentence: "Alder will very seldom crack...."

https://www.buildwithrise.com/stories/benefits-of-alder-wood

^Pile of salesmanship horse poop for the most part. Yes, it is cheap and soft, and better unstained. That’s about it.