I don't think it's debatable that there are people out there familiar with WordPress who don't like it much and are looking for something else. Whether this is

I don't think it's debatable that there are people out there familiar with WordPress who don't like it much and are looking for something else. Whether this is 90%, 50%, or 1% of WordPress developers doesn't matter much. Even in the worst-case scenario it's still going to be a big enough niche if you're able to reach them.