How can we get the USDA Plant Hardiness GIS data released as Open Data?

At the beginning of this year, the USDA released a new Plant Hardiness Zone Map:

Images of the maps are available for free download, but the underlying GIS data is not:

This data set would be incredibly useful for anyone creating a gardening or agriculture-related app, but it is only available through a vendor that provides commercial licenses that are too expensive and restrictive for most independent developers, and useless to anyone who wants to create an open data set. I've sent in several inquiries through the USDA contact form, but haven't heard back. Any suggestions or assistance on getting this data released?

Additional background and context

Climate Source, the data vendor, only sells single user licenses online:

Here is their single user license, which, unfortunately, disallows just about anything I could possibly want to do with the data, such as build a web app:

I contacted Climate Source a few months back for a license that would allow the uses I wanted to make of the data. The following is a summary of the salient points from that email exchange:

1) 'Server' licenses are $6k for a one-year agreement. Additional years are $4k, and they won't do anything longer than a four-year agreement for $18k, certainly not a perpetual and irrevocable license. According to the sales person, these are standard fees and terms for a commercial license.

2) The licensed data may not be republished in bulk. Licensees must put in place measures (such as a CAPTCHA) to prevent 3rd parties from scraping the data, and Climate Source requires prior approval of these measures before the app is live (so much for using this data in creating any open data sets or open source apps). According to the salesperson, these measures are supposedly being required by the USDA and OSU, rather than Climate Source. The salesperson points out the CAPTCHA required to do a zipcode-based lookup on the USDA website as 'proof' of this requirement. 

3) Further, according to the salesperson, the USDA (due to budget cuts) can no longer afford to create new data sets like the plant hardiness maps and just give them away. However, the raw climate data used was already collected by NOAA and is freely available, and I don't think that processing the data to produce the maps could have been all that expensive, regardless of how sophisticated the algorithms that were used.

To add final insult to injury, Climate Source has themselves been using this data to create various mobile apps, so essentially the licensing fees are a barrier to entry to anyone who might compete with their 'Climate Wise' apps:
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