This is my first post after lurking for a while, and after joining only last week.
Anyone holding a grudge against Frank Lampard is behaving in an unreasonable manner.
First of all, no one can possibly blame a player for preferring to play in the Premier League. When it became clear that Man City wanted to keep Lampard for the full year, he quite reasonably saw that this was the thing to do. The Premier League is just more important than MLS -- and this is no knock on MLS, as the same thing can be said about every other league in the world outside of Spain and Italy.
The only blame in the situation is with NYCFC, which should have anticipated the possibility (albeit unlikely at the time) that Man City would want Lampard for the whole season. NYCFC should have announced from the beginning that Lampard would be coming to the league in the summer, just as Beckham, Henry, Cahill, Keane, and even Dempsey did, and as Gerrard will be doing this year. After such an initial announcement, Lampard's possible early arrival would have been a bonus; and no one would have been complaining when Man City decided to keep him for their full season.
NYCFC's botching of the situation unfortunately cast the Man City connection in a bad light, which somehow placed fans of the club on the defensive and gave the team's detractors ammunition. But no fan of NYCFC should ever be apologising about the club's connection to Man City; rather, the City-City link is something to be proud of.
Furthermore, the whole thing will certainly work out in NYCFC's favour. Lampard can finish the season at Man City, take a few months off, and then join NYCFC in early August. That will be just fine, as MLS's come-one-come-all playoff format (now there's a knock on MLS) ensures that the most meaningful matches are not played until that time of the season. In fact, Lampard coming off a summer break will be more useful to any potential NYCFC playoff drive than he would have been had he joined the club in its pre-season training and had he been playing in every match from the season's start.
Considering that Man City fans were able to welcome back Carlos Tevez after he refused to come on in a Champions League match, after he said that he never wants to go back to Manchester, and after he stayed home in Argentina for months boycotting the team, fans of NYCFC can certainly welcome Frank Lampard after he did nothing more than elect to stay with the defending champions in the best league in the world after the club's manager had made repeated public comments about his desire to keep the player.
Lampard did absolutely nothing wrong in staying with Man City at Pellegrini's insistance. And he will be NYCFC's biggest star and top draw once he arrives -- the game against the Galaxy and Gerrard in late August will be the most celebrated event in MLS since the arrival of Beckham. All fans of this team should not only accept this, but enthusiastically embrace it.