This is interesting;
[FONT=Verdana, Arial, Geneva]And thus she that vilified David brought a reproach upon herself, as barrenness was always reckoned, and no one descending from her arrived to royal dignity, and sat on the throne of David; and so it was ordered in Providence, as Abarbinel observes, that the seed of David and of Saul might not be mixed. [/FONT]
Source: The New John Gill Exposition of the Entire Bible
Michal's barrenness was not necessarily the result of Divine judgment. It may be that David never had marital relations with her again. Nevertheless, the principle stands: there is often barrenness in the life and ministry of the overly critical.
Source: David Guzik's Commentaries on the Bible
David was contented thus to justify himself, and did not any further animadvert upon Michal's insolence; but God punished her for it, writing her for ever childless from this time forward, 2 Samuel 6:23. She unjustly reproached David for his devotion, and therefore God justly put her under the perpetual reproach of barrenness. Those that honour God he will honour; but those that despise him, and his servants and service, shall be lightly esteemed.
Source: Matthew Henry Complete Commentary on the Whole Bible
Therefore - Because of her proud and petulant speech and carriage to David, which God justly punished with barrenness. No child - After this time.
Source: John Wesley's Explanatory Notes on the Whole Bible
So it would seem that upon examining many Bible commentaries, the idea that Michal was struck barren is not just the "P/C spin" that the OP would have us to believe. It's a pretty widely held belief in all of Christianity.
This emphasized sentence is the one statement that summarizes my thoughts on the thread, and on the lessons learned here from Michal's response;
Michal's barrenness was not necessarily the result of Divine judgment. It may be that David never had marital relations with her again. Nevertheless, the principle stands: there is often barrenness in the life and ministry of the overly critical.