I have met people hired under the O1-A and they fit the bill pretty neatly. Think R1 profs publishing in Nature/Science/domain equivalents. If you have exceptional talent, you can 100% get in.
I think the issue is expecting a masters/phd to ensure access to th US labor market. This greatly distorts the fact that for most software engineering positions a bachelors is enough (if necessary at all), crowding the domestic market.
The US should not allow the pipeline of jr->sr engs to be culled for the sake of accessing cheap foreign labor. Given the necessity of software to run the modern economy, it really is a national security issue.