There are a number of reasons why wages might not rise that have nothing to do with free market supply and demand. The most obvious is you could control wages by being the owner of inelastic goods your workers require to live, such as housing. I think this is how the feudal system worked originally, workers produced cereals but the Land and the worker's cottages were both owned by the Landlord. If the price of bread…
I've read a couple of anecdotes, though never could find anything concrete: the government was more than happy to offer industry the use of H1B visas for high-tech employees.
That way, wages would be suppressed, and the US military industrial complex would be able to outcompete adversaries as warfare was becoming more and more software based.
It might be interesting to see if companies in and around the DC metro area (where many of the associated MIC contractors do business) have a higher rate of acceptance for their H1B requests.
For example, if random banks and insurance companies in the DC area were able to get 2x - 3x the amount of visa approvals vs similar industries in other metros, this would, over time, push wages down in the area for all programmers. This would save the government billions of dollars per year considering how much the US spends on defense.