Crest's reaction is typical of this industry.
Everything is man made, except the things made by machines, but the machines are man made!
Regarding your photos, I do think you are being a little "picky."
The tile hole at the shower control that is still visible on image 3 needs re cutting.
But the rest whilst not perfect, in my opinion any remedial work, cutting out tiles and re doing could even end up looking much worse.
If this is all you have found in a home rushed by Crest for their year end figures (31 October), you've done pretty well.