The main argument against the 50 meter facility was that they couldn't go outside the footprint of the existing pool. If they did, the cost to upgrade to today's earthquake and other specs was cost prohibitive. So the decision was made to "replace" the existing pool.

The problem was that when the contractor got going, they ended up having to do a bunch of code upgrades anyway, and the best kept secret at BYU was that the finished product they have now cost almost exactly what a new 50 meter facility would have cost, extending the west wall of the Richards Building.

Some mid-level manager(s) made some very poor decisions. Cost ended up a non-issue. If they knew then what they know now, I'm reasonably sure that Pres. Samuelson would have signed off on the 50 meter facility. So not all of it was on him. He was acting on the advice of the BYU facility people that put together the options.