Silly Question About Cutoffs And Supply Lines

So I'm far from an expert but what I've typically seen is either copper pipe with a compression fitting, or iron pipe with a threaded fitting. The piping I'm currently working on is copper with a threaded fitting sweated on.

Why would someone sweat on a thread rather than just leaving the bare pipe for a compression style cutoff? Is this just a matter of preference?

TIA

Yes, it is just preference. The majority of plumbers would use a compression stop.

If it is a male thread you can screw the stop right onto it. If it is female, use a brass nipple between it and the valve. We don't usually use threaded adapters because it takes longer to get them at the correct point and solder them on.