Why? We overachieved by finishing 2nd last season, our squad isn't the 2nd best in the PL. If you are delusional enough to think it is, then you need to change sports.
Secondly, the very next rival to us, Liverpool significantly improved their squad, spending bucketloads, City strengthened, Chelsea strengthened, Spurs already have a superior XI to us, so for you to be SO SHOCKED to see United struggling for top 4 is laughable. There are 5 very good teams and managers, and some United fans throw all their toys out of the prams at the first sign of danger. I've no time for that kind of fan.