So once per turn when you get in HQ you get to draw 1 card and force the corp to draw 1 card. That word "force" is odd, the text could read "you may draw 1 card, if you do the corp must also draw 1 card". The text on the card hints that main effect is making the corp draw, the text I wrote puts the emphasis on the runner drawing. I think this is a hint by FFG how Polyhistor is intended to be used, as a way to force the corp to draw cards.

Here's the problem with that: you force the corp to draw at most 1 extra card each turn. In a significant number of cases that would help rather than hinder the corp. You could not use the ability but then you lose out on your draw as well. So the ability is weak at least part of the time. The absolute best case scenario is when you can get the corp 5 or 6 agenda's in hand, but that's kinda unlikely, though not impossible.

To make most of the ability you have to get the corp to draw more cards. Laramy Fisk: Savvy Investor, Fisk Investment Seminar and SYN Attack help here. And I do see some value in Polyhistor as Fisk's console (I guess it's thematically Cambridge's, but with regard to effect it's clearly Fisk's). If you play Fisk with Polyhistor and on click 1 do Fisk Investment Seminar, and on click 2 an HQ run (e.g. Account Siphon) you end up giving the corp 5 cards and drawing 4 cards yourself. Without Jackson Howard around and if archives is open the corp will likely end up agenda flooded after their next turn (since they don't need to discard until the end of their turn) and you can go for a heist with Legwork.

That said, is the 1 extra card you force the corp to draw worth not getting a credit per successful run with Desperado? It's a difficult call to make for a Fisk deck. For any other deck it's not so difficult: nope.