I don't really like the ship to be quite frank, and I know a lot of others do. That, I'm fine with.

But I suppose if someone needs to know why:

The underlying reason people ship the two to begin with is that their historical counterparts were married. Although what's not expanded on is the fact that it was very likely a political arranged marriage. By the time Shoutoku Taishi was wedded to Tojiko no Iratsume, Soga no Umako has killed at least two of Shoutoku Taishi's relatives and likely Tojiko, herself was quite young. I somewhat dislike this missing context because it feels like it sanitizes history a bit and also is misleading about a practice that's still used to consolidate political and economic power.

(I will note these days more arranged marriages are done with the consent of the two being wedded so that's an upgrade at least)

The latter reason is drastically more personal:

When I had turned eighteen, I was planning to study out of state (because I just really wanted to get away from family without really understanding why). Around that time my mom had talked about a friend who'd she considered marrying me off as a form of economic financial security (he was in his 30's and part of the US military).

This later turned out to be a bluff; but for about a year or two there was always a sense of uneasiness of that my future would be upended. Only upon later reflection after the bluff was called did I realize there was other issues with this kind of relationship (it should be apparent, I hope).

Though the existence of this bluff in of itself has it's problems I'd rather not dive into right now.

But I hope this provides some clarity on my disdain of the 'They were married IRL' argument and just my feelings on why I'm so adverse to presentism in marriage in general.