It is not a matter of quality. You can get great sounds from a computer and many albums have been made on nothing but a laptop or even an iPad or GameBoy. Quality is not the concern.
There are good reasons for wanting hardware synths, though, even digital ones.
- They start up instantly and generally never crash.
- They have many knobs and controllers for direct control of the sound
- They are usually ruggedly built to survive gigging on stage
In other words, Built for performance.
- Even the most versatile ones give you a limited palette of sounds, forcing you to focus instead of getting lost in the distraction of 5,000 different plug-ins
- Creating your own patches is often a more free-flowing and intuitive process because of the tactile connection to the synth.
Potentially more inspiring
- Analog synths do make sounds that are hard to emulate. The best computer emulations are 99% of the way there, but that last 1% is like the fizz at the top of a freshly-poured soda. It adds an ineffable zing to everything you play.
- Some synths are so physical they only exist as hardware and couldn't work any other way. There's really no way to play a theremin without having the genuine article.
Analog has its charms
There is one great, looming con to hardware, though:
Stick to the computer while you're learning. The mistakes and the lessons learned from them are cheap, and the array of options is vast. Graduate to hardware when you can't help yourself. That time will come, soon enough.