Submit buttons in Zurb: do you use an <a> or? - zurb-foundation

Question

I'm not really getting the rationale behind the overabundance of <a>s in the code at http://foundation.zurb.com/docs/components/buttons.html; and the lack of representation for the other elements.
Short of one mention, and one line, both under the Accessibility section, no mention is made of any other element (why not <button>, or <input> for example?). It almost seems as if (due to the overwhelming overrepresentation) the documentation were saying "we really designed this for <a>s". Is that really the case?
(Small aside: the line that mentions using other elements, I have a problem with: If there is no <a href=""> then simply add the tabindex="0" to the div or span to make it focusable. If a button is focusable, I expect to be able to trigger it with the spacebar. Unfortunately, when you've got a div or a span, you can't. So is this really useful, or even constructive?)
I get that you can use <a>s for cases where no forms are involved, but what of your standard "submit" button where a form is involved? Wouldn't using a <button> resolve all the issues that you would have using an <a>? 1. It's focusable. 2. When focussed, you can trigger it with the spacebar. 3. You can conveniently press <Enter> to submit the form. What do other folks use for your submit button/s?

Answer 1

The buttons tags are usable in foundation 5. There is not a lot of documentation on it but (and I tested it to make sure I was correct) the <button> tag works as normal.
The <a> tag is used on the example site sure, but that doesn't limit its use when working with it.
You should still use <button> with forms and use <a> for links.
If you look at adioso.com (they use foundation) and inspect their forms, they use buttons for functional uses outside of links.
<form class="flight_search" method="get" action="/search_form">
<div class="search_form_inputs">
<ul class="row">
<li class="columns large-3 small-12 medium-6">
<li class="columns large-3 small-12 medium-6">
<li class="columns large-3 small-12 medium-6">
<li class="columns large-3 small-12 medium-6">
</ul>
</div>
<div class="search_sundries">
<div id="passengers" class="awesome-search">
<div id="submit-wrap">
###<button id="submit-btn" type="submit" class="search_button" tabindex="9">Find Flights</button>###
</div>
</div>
</form>
Check the above code. The example website isn't a very solid representation of what foundation can do but play with it a bit and you'll see its a very solid framework.