Its not even close. Beckham had a lot of credit in the bank with the team. There were years, in some of our best seasons as a club, where Beckham was our best player. He was far more influencial at the time the Giggs and Scholes; with Keane and Van Nistelrooy being the only players at the time who could be considered better than him. He was a credit to the club on and off the pitch, so when this row with Fergie occured, no one could really fault Beckham's reaction despite the fact that Fergie's frustrations were understood.
Pogba came and imo was hyped to the moon due to the fact that he left United in the first place. I don't believe Pogba would ever have had that celebrity without United fans consistently going on about the one that got away. It's the reason why a lot of fans didn't know how he actually played, and were shocked during both the euros and by November 2016 when they realised that he wasn't the Yaya Toure regen they had been sold on. Anyone who knows anything about Italian football would understand that the midfield translation due to their heavy focus on keeping things central and playing with deeper defenses meant that Pogba had the time and space to drive, play beautiful passes and look physically dominant week in week out; with his position on the pitch not actually existing in the English game ( very similar to Veron). This need to find a position for him and the lack of quality in the team at the time, meant that Pogba was a much bigger focus and superstar than he was supposed to be. Which gave him the confidence to publicly reject playing in a deeper role in 17/18 ( where he had a fantastic first half of the season) and began the toxic warfare with Mourinho which divided the dressing room. This is when his agent and brother started spouting rubbish to the media, promoting more negative focus on United. In the derby, he even died his hair blue, some like to make it out to be naive, but that began a trend of Pogba and the team around him doing stunts that brought negative attention to the club with his fans claiming naivity. The hope was that Mourinho leaving would bring peace to the club, but the Pogba circus continued. United were weakest in the calender year 2019, and when United needed him, through injury and press releases from parties around him, Pogba wasn't there. In a club trying to rebuild and start a future team, Pogba was a key stumbling block, particularly in the first half of the 19/20 season. Yes he was seemingly injured, but the perception was that Pogba would never play for United again, and this when when his agent was loudest, criticizing the club both on and off the pitch with Pogba seemingly on the sideline saying nothing; showcasing his lack of care for the club to some. Then Bruno came and the impact was instant. He was proof that Pogba's average performances and poor leadership were not because of surrounding players, but rather weaknesses of his own. Since then, United haven't felt tied or even in need of Pogba and Pogba's team have been a bit more quiet and have been pushing more for an extension. 2 years ago, United would likely have paid Pogba what Raiola demanded, now United have the superstar talent and performers that allow Pogba look redundant. Pogba hasn't been a positive influence to the team in the time he's been here, Beckham clearly had an excellent impact and influence, so the fan reactions have been different and deservedly so.