PSG not doing really good lately and today they're just fell to a 0-1 defeat against Olympique Lyonnais, This froze the Parisian team's points tally at 66, still leading the league with a 6-point lead over Lens and Marseille.
Even Lionel Messi headed straight to the dressing room after the end of the match, without greeting the Parisian fans.

In fact, PSG fans booed Messi at the beginning of the game when the squads were announced, so it’s quite reasonable behavior.
In general, I can understand them - the arrival of Messi led to the fact that PSG began to relegate from the French Cup and the Champions League in the 1/8 finals for two years in a row, and Messi himself disappears in important games.
From such a promoted footballer, they expected exactly more.