Buttonのコメントを外したときにテキストがくっつくのは何故？

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation";
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml";>
<Grid>
<!--<Button Margin="10">-->
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Row="0" Grid.Column="0" Text ="0-0"
HorizontalAlignment="Center" VerticalAlignment="Center"/>
<TextBlock Grid.Row="0" Grid.Column="1" Text ="0-1"
HorizontalAlignment="Center" VerticalAlignment="Center"/>
<TextBlock Grid.Row="1" Grid.Column="0" Text ="1-0"
HorizontalAlignment="Center" VerticalAlignment="Center"/>
<TextBlock Grid.Row="1" Grid.Column="1" Text ="1-1"
HorizontalAlignment="Center" VerticalAlignment="Center"/>
</Grid>
<!--</Button>-->
</Grid>
</Page>