I see three factors that might afflict Synflow but I think you are right to highlight the language issue. Proprietary languages often struggle for adoption.
The question has to be how does C~ compare with such offerings as SystemVerilog and perhaps to a lesser degree SystemC...but also how the IDE can connect with descriptions in those languages.
A second factor is graphical design. Textual languages have dominated the IC design area for decades, despite one or previous attempts to introduce graphical design front-ends that failed to gain traction.
A third factor is Synflow's avowed intent to steer clear of software. This is a bit of double-edged sword. On the one hand they are probably right that there are two distinct audiences. One is system/software developers who are not interested in hardware.The second is hardware engineers. However, high-level hardware engineers for a long time had to have an eye on the software. Often they are choosing whether something should be software programmable or accelerated in hardware.
So there are fundamental questions to be addressed but all could be resolved in Synflow's favor if this tool produces high QoR designs in a fraction of the time of conventional design AND it could pass designs over to an SoC RTL to gate-level desgn process.
It looks very appealing for small to medium projects in companies thats can't afford big tool chains from synopsys or others. Is the simulator included ? Is it possible to simulate mixed design with C~ top level and some VHDL/Verilog IPs ? What about cosimulation ?
thank you for your comment, and this is an interesting question that you're asking. We hope to get some early adopters for whom this won't be an issue, and work with them to make the language evolve until we feel comfortable it is ready for standardization.
It sounds like they have aimed for a level of abstraction that is above RTL but below untimed, algorithmic HLS. This could be very appealing, but will designers warm up to the idea of capturing their designs in a new, proprietary language?