[Update: I see you mentioned this, and other unlibertarian proposals Stiglitz made, in your excellent review.]

Well, while I think your characterization of progressives is a bit off-track (full egalitarianism seems more of a communist or socialist trait, rather than a “progressive” trait [progressives being anything just left of center to democratic-socialists), I do see the irony. At the very least, progressives should at least support reducing the time intellectual property laws monopolize certain new products.

Interestingly, some progressives may be doing just that. One such example is Joseph Stiglitz, who in his book Making Globalization Work at first suggests reducing or eliminating patents on pharmaceutical products exported to the Third World. Stiglitz, of course, doesn't take his logic to its fullest implications, but nevertheless concedes that current patent laws have made it very difficult for the Third World to acquire drugs which would otherwise have been inexpensive enough to afford (through third party manufacturers).

Furthermore, he makes some broader claims (although, the context these following statements were written in were one of agreement with at least some patent laws; see my review of his book here). Stiglitz writes,

“…[With] the enclosure of intellectual commons, there is a loss of efficiency… “Monopolization may not only result in static inefficiency but reduced innovation.”

Nevertheless, you are right that intellectual property laws do run contrary to egalitarianism.