This is a great question to consider. In a sense, the ending of the play and the way in which it refers to the feud between the Montagues and the Capulets ending is a fitting conclusion, because it showed that the death of Romeo and Juliet was not entirely in vain and that something positive was gained from it. However, on the other hand, it is possible to take a somewhat different and more depressing view. Consider how the Prince closes the play, and in particular pay attention to the dark imagery he uses:
A glooming peace this morning with it brings.
The sun for sorrow will not show his head.
Go hence, to have more talk of these sad things;
Some shall be pardoned, and some punished;
For never was a story of more woe
Than this of Juliet and her Romeo.
The "glooming peace" and the way in which the sun is personified as suffering from grief plunges the ending of this play into an unremitting darkness, questioning the price that was paid for the peace that has been achieved. The line "Some shall be pardoned, and some punished," likewise indicates that the punishment of Romeo and Juliet's death is something that will continue long after the ending of the play. I wouldn't personally describe the ending of the play as an anticlimax, but the high price of the peace that has been achieved definitely overshadows the ending.