GHWB had chance to flip the court to conservative, but he gave us one flaming liberal and one conservative. Souter was recommended to him by Warren Rudman, a senator from NH at the time.
Souter had worked with Rudman in Rudman's NH DAs office in earlier years and Rudman knew him well. Otherwise he was a mystery. That was a time when candidates were really looked at for how they might rule on abortion. Pro-abortion GHWB took Rudman's advice and appointed the mystery man who later voted to uphold Rowe v. Wade.
There is a story of how Rudman and Joe Biden were high fiving after Souter voted to uphold Rowe.
I think these misses have been intentional by the Bushes.
On second thought W gave us Roberts and Alito, so perhaps you are right - maybe this is an intentional manifestation of the Bush family’s infamous principle-lessness.