I'm not complaining on the use of the ampersand, but unlike many people seem to believe, it's not semantically equivalent to "and". Beyond just joining two items in a phrase, the ampersand marks an association between them and emphasizes it as a single definite idea, a "thing".

Ampersands are often used to mark brands, names and cultural items made up of multiple components: Johnson & Johnson, Dungeons & Dragons, bread & butter, fish & chips, Gold, Smith & Associates.

If I say "I had some fish & coleslaw" that would make a few people wonder if this is some popular recipe they should google.