If someone wanted to, sure, an extension could be made.
With the prevalence of free online minifiers, I doubt many extension makers would see any profit in taking the time to create one though.
I use JSCompress all the time. But, being able to do it inside DW would be a lot easier.
...if they did it the right way, definitely.
I've seen some terrible extensions that actually make the process they're menat to fix, worse.
There was a time when DW had a huge group of extension makers that would basically compete against each other to see who could make the best version of a given extension. That time is long gone though. All that's left are pretty much 2-3 professional studios that make good paid extensions, and a handful of hobbiests with wildly varying levels of ability.
If you create Sass files you can tell Dreamweaver to conactenate and compress the files (or just compress)
My age is showing once again, many apologies. Have edited my post,