Getting in better players is a good thing. I have no problem bringing in better players (although I'm not sure that's what actually happened; we'll see). The problem is when that much of the starting lineup is turned over, the precious little chemistry which had been built up over the first few months was instantly gone. If you look at the
results map, you can even see it: Kreis had managed to finally get a consistent roster and overcome injuries, including a notable one to Villa, to put together 5 wins, 2 losses (RBNJ and Revs), a draw. That last win is when Pirlo comes in, and he worked with Poku to beat Orlando City 5-3. After that however, once Lampard and other reinforcements start coming in (and opponents get to look at MLS Pirlo on tape) NYCFC wins only 1 in 7, with 5 of them losses. NYCFC then puts together a solid 3 game winning streak with a win at Vancouver the best before they knocked out of the playoffs chasing a win in DC that really should have been a draw (which would have been a good result early in the season). After that, Kreis goes experimental, and NYC doesn't win again.
The main issues with an expansion team are depth and chemistry. NYCFC got hit with some big injuries in the early part of the year and lacked the chemistry and depth to overcome it. When NYCFC started to have something cooking, Kreis was forced by the DP contracts to throw that out of the window and had to start back at square one. There were plenty of signs of improvements despite the horrible roster given to Kreis by Reyna & CFG. I think Kreis could have gotten NYCFC to the playoffs with a full offseason with his DPs. To not give him that chance based on roster turnover which he can't reasonably be blamed for is insane.