No it's a poor error and I expect better.
But it's still nonsense to suggest the man in the street is just as capable goal keeper.
Rib gonna Rib, to be fair.
Maybe not Migs himself as he does not play the sweeper role well, but a Migs-quality keeper, from a shot-stopping perspective, is fine as the backup who'll be lucky to get a few games a season. No one is coming here to challenge Alisson for the #1 spot, so whoever the backup is has to come with the understanding that barring injury, he's only looking at domestic cup games, which is probably no more than 10 games if we make deep runs in both competitions.
I expect Migs will want to leave in the summer and go seek a starter role somewhere else, where he should clearly find one. I imagine we'll replace him with an older goalie whose best days are behind him but still has enough left in the tank and is willing to play a backup role. Would not want to have a young kid like Grabara / Kelleher as the backup and have to depend on them if Alisson goes down with an injury.
You're not going to get a top quality goalie to agree to come in and only play as little as 2 games in a season, so the drop from Alisson to whoever the backup is, Migs or otherwise, should be pretty obvious and expected.