There weren't any centers worth taking at #18, but yeah, their two picks at the end of the third round was a great time to take a shot. Instead they went with Tiernan who I liked and you could call BPA, but then they extended O'Neill so Tiernan might be a starter in 2029. And then Jakobe Thomas, who like Felton the year earlier I thought was a multi-round reach, a one year starter in college with a scary high missed tackle rate. This was a weaker draft class than previous years, but they didn't need to take projects with those picks who won't play for years. Centers Sam Hecht and Connor Lew would have been great selections there IMO.
Yup, I think a lot of blame should go on Ryan Grigson, Kwesi's assistant GM who was essentially the top 'football' mind in the front office since Kwesi didn't have a background in that. Grigson was the Colts GM who somehow bungled the team in the midst of having Andrew Luck in his prime. The Wilfs also extended him a year ago, but Teasley made the smart move of changing his job title, prompting him to quit and probably saving the Wilfs a good amount of money.
My guess for the reasoning why is because the front office had already completed the scouting for the college season and scouts are almost always fired/promoted right after the draft. Which is strange given you let them do a great and then fire them. When new GMs are getting hired at the start of the calendar year, it's still usually the previous regime's scouts making the draft boards for the upcoming draft in the spring.