StatefulWidget rebuilding unnecessarily after Navigator.push()/pop()

main.dart

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Page1(),
    );
  }
}

class Page1 extends StatefulWidget {
  @override
  Page1State createState() {
    return new Page1State();
  }
}

class Page1State extends State<Page1> {
  var i = 0;

  @override
  Widget build(BuildContext context) {
    i++;
    print("rebuild $i");
    return Scaffold(appBar: AppBar(title: Text('Page1')),
        body: Center(
            child: Column(mainAxisAlignment: MainAxisAlignment.spaceAround,
                children: <Widget>[
                  Text('Page1 build counter: $i'),
                  RaisedButton(
                    child: Text('Navigate to page 2'),
                    onPressed: () {
                      Navigator.push(context,
                          MaterialPageRoute(builder: (_) {
                            print('inside MaterialPageRoute builder');
                            return Scaffold(
                                appBar: AppBar(title: Text('Page2')),
                                body: Center(child: Text('$i')));
                          })
                      );
                    },
                  )
                ])
        ));
  }
}