Lots of companies would like to stick to a tool that they already know how to use. Even keeping GrexIt out of the picture, the tips we suggested can really help. Do give this a try.
Definitely agree, and Grexit is great for that and I do really like the tips. Not trying to denigrate here. Just pointing out it's a factor in some settings.
I understand where you are coming from, and that is one of the biggest challenges for us. We really feel that with an email centric approach, we can help companies which want to do light-weight collaboration, and are fine with trading off very rich functionality for a simple email centric workflow.