Any reason to not use constructor to bind functions?

export default class AddPlayerForm extends Component {
    constructor(props){
        super(props);
        this.onNameChange = this.onNameChange.bind(this);
        this.onSubmit = this.onSubmit.bind(this);
        this.state = { 
            name: '' 
        };
    }
    static propTypes: {
        onAdd: React.PropTypes.func.isRequired,
    };

    onNameChange(e) {
        const name = e.target.value;
        this.setState({ name: name });
    }
    onSubmit(e) {
        if (e) e.preventDefault();
        this.props.onAdd(this.state.name);
        this.setState({ name: '' });
    }
    render(){
        return <div className="add-player-form">
                <form onSubmit={this.onSubmit}>
                  <input
                    type="text"
                    value={this.state.name}
                    onChange={this.onNameChange}
                    placeholder="Player Name"
                  />
                  <input type="submit" value="Add Player" />
                </form>
              </div>
    }
}