1) I know they don't need my email in order to analyze my site, so I am immediately suspicious. There is no checkbox for agreement with a privacy policy, nor is there language stating I will never be spammed, etc. Thus, I did not try the demo.

2) If they really do demand my email address to try their service, they should let me see a screenshot, at least, so I can get a sense of whether or not I want to risk giving them my email address.

I think that this errs on the side of giving too little information to make an informed choice about wanting to use their service. There are many sites that will, without requiring an email address, do some basic SEO analysis for me. Without knowing what their site does, I was not enthusiastic enough to actually try their product.