Recent comments associate hiking a baby into the back country with saving the environment, but none of them claim a net benefit to the baby, which more or less describes the priorities.
One online comment describes the “awesome backpacks” that are available to haul a baby around. If enough townies with cool backpacks subject babies to the easily foreseeable and potentially fatal risks of the backcountry, which include deer ticks, predators, or simply falling down, the unfortunate epitaph might be “RIP baby. The environment is sorry.” While I’ve spent a lot of time in the back country, I wouldn’t take my baby out there on an ATV, much less allow him (or Grandma) to be packed out there by any of those eco-saviors on foot, no matter how gloriously trendy it might be.
As for motorized vehicles, it seems unlikely that any part of the wood cabin, (produced by mechanized logging operations), or the aluminum canoe (produced by mechanized mining operations), got to the lake without first being transported on a vehicle, on a road. Even Beacon Hill Park has a road in it, and that is one park I would take my baby to.
The issue is not and never has been about motorized vehicles in parks or sacrificing babies to save the environment. It’s about getting to the lakes on the existing road. The fact the townies can’t get their eco-sensitive cars in there is no reason to deny access to the rest of us.