It frequently is easier and arguably more convenient to put the connection in "a box" on the wall.

It is acceptable to most to have it either there or in an adjacent cabinet or even in a basement area below.

I don't even know where Kentucky is. YMMV

It’s legal and fine. Be picky about something else.

Not sure if you mean that I am being nasty. If so, that was not my intention.

Only as someone that has a line through the cabinet while it may be normal it also takes up room in the cabinet that I can not use. You might use the box as some thing that would make future buyers happier than seeing the line through the cabinets.

I also hate that I cannot use those cabinets to store food that is not in a container because if there is a bad ant year, again, the ants or other bugs have entry to all of the base cabinets.

The water line is frequently run in the space beneath the bottom shelf or beneath the bottom drawer. No usable space in cabinet lost.

Too bad the water line installers for my refrigerator did not know that, Stax.

Yes, that is too bad.

It is often no more difficult to run the water and/or drain that way for Dishwashers that are not immediately adjacent to the sink

Clearly one doesn't "bury" the isolation valve underneath where it is not accessible! Doh.

That space under the bottom is not used and thus no usable space is lost.

Had they run it in the top of the cabinet, you never would have noticed. They should be punished just for that.

Yup!

I lean toward under for water - frequently water source for ice box is coming from basement below. Lean toward top to create vacuum break on dishwasher drain to garbage disposal knockout.