Sounds like Dave (in the example) is conformist (adjective) or is a conformist (noun).
1. a person who adopts the attitudes, behaviour, dress, etc of the group to which he belongs
3. of a conforming nature or character
Collins English Dictionary. Copyright © Harper Collins Publishers
graded adjective & adjective
Someone who is conformist behaves or thinks like everyone else rather than doing things that are original.
⇒ He may have to become more conformist if he is to prosper again.
Mr Gordon now feels forced into an ever more conformist way of running
A conformist is someone who is conformist.
Advanced English Dictionary. Copyright © Harper Collins Publishers