<p dir="auto">As you can see in the image bellow, If we go on with the example of the Hoizontal Form and don't have the checkbox, then the button will render without margins and ugly.</p>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://camo.githubusercontent.com/dd2db93900f92758035eb5f15f91cb61790d8d5fe4e1f063b0ea537c0368c7c1/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f3837383636372f3930333937382f64343837303466322d666262382d313165322d383262342d3633373363656165366335662e6a7067"><img src="https://camo.githubusercontent.com/dd2db93900f92758035eb5f15f91cb61790d8d5fe4e1f063b0ea537c0368c7c1/68747470733a2f2f662e636c6f75642e6769746875622e636f6d2f6173736574732f3837383636372f3930333937382f64343837303466322d666262382d313165322d383262342d3633373363656165366335662e6a7067" alt="bt_bug" data-canonical-src="https://f.cloud.github.com/assets/878667/903978/d48704f2-fbb8-11e2-82b4-6373ceae6c5f.jpg" style="max-width: 100%;"></a></p>
<p dir="auto">But if we have the checkbox, it will render good.</p>
<p dir="auto">Why don't have something like button class for divs? (Same as what we have in the example for checkbox):</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="&lt;div class=&quot;checkbox&quot;&gt;
    &lt;label&gt;
        &lt;input type=&quot;checkbox&quot;&gt; Remember me
    &lt;/label&gt;
&lt;/div&gt;
&lt;button type=&quot;submit&quot; class=&quot;btn btn-default&quot;&gt;Sign in&lt;/button&gt;"><pre class="notranslate"><code class="notranslate">&lt;div class="checkbox"&gt;
    &lt;label&gt;
        &lt;input type="checkbox"&gt; Remember me
    &lt;/label&gt;
&lt;/div&gt;
&lt;button type="submit" class="btn btn-default"&gt;Sign in&lt;/button&gt;
</code></pre></div>
<p dir="auto">In the horizontal form example (<a href="http://getbootstrap.com/css/#forms-horizontal" rel="nofollow">http://getbootstrap.com/css/#forms-horizontal</a>) everything looks great because the checkbox div has 10 pixels of top and bottom margin.</p>
<p dir="auto">However, if you delete the checkbox div then the button is right up against the text field. Unless you have a checkbox or radio button at the end of your form it will not look very nice without adding custom styling.</p>