I think you're right. And we've had a "golden age" end twice already: first in the 1980s, which was double-whammied when they cracked-down on contractor labor practices, and again after the dot-com burst. Both times left a lot of carnage and a lot of bitter people who swore off the industry.
And both resulted in a labor shortage a few years later.
I suppose an argument could be made that unionization would increase the output of the technology sector by virtue of preserving the labor pool, along with all the expertise and domain that would normally evaporate, during down-cycles.
Also, lots of people seem to be equating unionizing to having some sort of fixed wage. In reality, it comes down to how the union decides to structure its contracts -- several unions simply dictate a minimum rate/wage, and leave room for negotiation. It's why SAG offers people minimum day and weekly rates and SAG movie star can negotiate a multi-million dollar contract.