As well as putting in a relatively heroic performance and being a thoroughly likeable lad, I think the reason we've all loved Seamus coming back in so much is that he's a connection to a different time for Everton, when things made a lot more sense, and there was a lot more stability.
Since we've entered into the Moshiri era (which I support fully, and think will ultimately be a force for good), things have been a bit all over the place - different managers, players coming in and out of the club very quickly, unrecongniseable performances from one week to the next.
It's been a very chaotic, unstable time for Evertonians and it's so comforting and reassuring that amid all the change and indecision, a Colossus like Seamus Coleman still stands granite-like, unaffected by the winds of change that have blown through Goodison Park. A hero for all the ages.
And that he cost us what some of our current shite players earn for a disinterested half of play doesn't hurt.
He's everything you can ask for in a footballer--brave, skilled, loyal, humble, etc.--minus so much of the garbage you get from 21st century footballers. Top lad.