I think it's actually a good move for the first gen. If they put out the CPU frequency, people would be comparing it to the intel parts. ARM and x86 being different architectures, a 2GHz M1 is going to perform differently than a 2GHz Core i5
There's been dozens of macs that have come out with a lower baseline frequency than the last gen. My ancient 2004 ibook G4 has a higher frequency than a 2020 macbook air, doesn't mean customers conflate it to be faster nor should they if your marketing was worth a damn.