All of these things are chaff and don't take into account the serious controversies and scandals that have arisen in his Moscow compound. He's a self-ordained cult leader. Then you have the controversies and damage done and continuing to be done in numerous other orthodox churches by his false teachings which are substantial.
Additionally, even if it was just one issue, that issue is the article by which the church stands or falls, to quote Luther. That is enough. But it is not just one issue, it is a large complex of important issues we disagree (to put it mildly) with. Covenant theology, ecclesiology, sacraments, law/gospel distinction, worship, etc. He was a signatory of the FV statement and still has not retracted it, though he has tried to sidestep some of the nomenclature. Who cares if he might have some decent materials on marriage and homeschooling? If anything he is the worst of all of the FV'ers because he tries to play both sides of the controversy. The others are clear about their deviations from Protestantism, he hides and disguises his. He is a wolf and perhaps the most dangerous figure in ostensibly Reformed Protestantism.