Lack a top pair defender to pair with Seider, and another 1C/2C.
Goalies are way easier to acquire thru trades and free agency then a top pair D or 1C.
Goalies are much harder to evaluate and much more likely to bust at that draft position than a F or D.
You should always take BPA with a pick that high, and not draft for need. That's what later picks are for.
Take a C or D with the first pick and worry about goaltending later in the draft.