I personally think it's a bit off that a crowdfunded project like this is offering a DRMed deliverable to its customers. I expect the choice of Steam is more due to convenience than a consideration of its DRM scheme, but I'd be much more comfortable funding this if supporters were given access to a unencumbered standalone release.
Steam is such a good, user-friendly platform nobody really cares that it wraps everything in DRM.
Even if the world ended and Valve had to shut down Steam I feel pretty comfortable in the assumption they would "do right" by their customers in the end times to get around the DRM issues.
With the exception of, for some reason, Portal 2 which was an unreliable disaster of buggy DRM at first launch and still requires me to disable my anti-virus software in order to actually get it to pass the DRM check and start. (Also, if you're offline the first time you attempt to actually start Portal 2 and presumably other modern Steam DRM games it won't run.)
