I watch a ton of football. Usually watch between five and all ten PL matches each week (though with half an eye on the matches). Shaqiri is almost always subbed off by Hughes, when they're defending a result. My personal take is that he isn't dependable defensively when push comes to shove.
And Son, Chadli and Eriksen are all defensive gods? We're not talking about a defensive player, we're talking about an offensive player who is under 5'7, of course he would be the first taken off when defending a lead. Mark Hughes is a good manager who knows what he's doing. He's also the first player Mark Hughes would bring on when chasing a goal.
You have your opinion, and I have mine on the player, but to describe him as overrated is an insult to a player who has worked pretty fucking hard for every opportunity he has gotten, and an insult to a player who has shown on every stage that he can be a game changer, whether its the euros, the world cup, the Bundesliga, The Premier League, Serie A, he's performed well and changed games, and that is something every football club should be looking to have in their team.