AS needs to insure that small children are seated next to a responsible adult or provide UMC service.
They can achieve this by waiving seat selection fees for an adult/child pair on standard fares. Airlines should not be allowed to extort fees from parents by threatening an unsafe condition for their children if they don't pony up. And by adding the UMC fee to Saver fares if a minor child is traveling on the ticket, refundable if the child ends up seated next to his parent (as if AS would ever let that happen under these guidelines). The additional charge would clearly warn the customer that with this Saver fare their child may be seated alone, but will be attended to by the Cabin Crew as a UMC. Under standard operating conditions, other passengers should not be annoyed by being asked to make up for Alaska's neglecting the simple solution here. But as long as passengers snipe at one another, instead of the carrier purposely creating the condition for increased profitability at their expense, there's little incentive for them to do so.