Just using whatever’s the most available and cheapest is definitely more punk and cool than using any kind of hard-to-find analog hardware synth (especially the overpriced ones).
The only problem is that there are way too many options when you use software and you’ll make music entirely differently because of all the available features and doodads these days. Even with some newer VA hardware, there’s too many options. It’s even worse with software.
I didn’t even realize how much of that mattered until after I had spent hours upon hours trying to write stuff when I realized my gear was the problem. The thing is, you won’t realize this until you get your hands on old gear. Then it will all make sense.
That said, I think *in theory* it’s possible to use software only, but you have to be super disciplined and super aware of what you’re doing to avoid things like using too many effects, too many voices, too many envelopes, too many anything, which will immediately make the music sound too contemporary.
It’s hard to say what kind of musician you are, so I would have to agree with teachu2die and exotika and recommend hardware. I’d recommend getting even a VA like an MS2000 or Supernova before any kind of software.
If you use a computer, you’re going to have to learn the hard way.