There are pros and cons to both approaches. I know you would likely say the SA approach is better, but I wouldn't... just because I don't think either is better than the other.
The simplicity of the SY1 is a big bonus. Sure, you can't save presets. However, there are only a few parameters to tweak when you go to a different sound, so it isn't a terrible burden. It's also a big perk to be able to just look at the top of the pedal and say, "here are my 'string' synth sounds." Twist one knob and, boom, you're on them. There's a strong appeal to that, especially for people who don't know anything about how to set up a modular synth. But, there are cons too. I've used pedals like that, and what I have run into is a lot of, "wow, I'd love this sound, if I could just tweak a couple extra things..." Pros. Cons. Trade-offs.
The C4 looks amazing. The tracking, the depth, the tweakability, the presets. So much awesome in one pedal. At an amazing price for what's packed in there. But...cons. It's complicated. A lot of people will be completely lost when trying to create sounds. And a massive userbase uploading custom sounds has the downside of requiring users to sift through garbage, or stuff they aren't interested in, or that just doesn't mesh with their rig or band or whatever. And a lot of people won't know what little tweaks they need to perfect their sound. I personally have run into cases where every tweak I made took me further from what I was looking for. Pros. Cons. Trade-offs.
I owned 2 SY300s. It's an amazing pedal. I hope to get an SY1 at some point. It looks every bit as cool as the C4 imo. Just...different. For now, C4 for me. And I'm excited.
To each their own. To me...both, hopefully.