Winks was superb under Pochettino, before it all went a bit pear shaped. He struggled to really find a place under Mourinho, and ended up looking a bit shite.
A bit like Dele, really, but he never really had the opportunity under peak Poch to stand out as much.
He's not as bad as he's looked recently - and could easily turn a corner - but I think a lot of the disdain spurs fans have towards him have come from his reaction to being dropped under Mourinho. The general image is of a player that isn't self-aware of his own shortcomings or bad form. Like Eric Dier.