The proper stance on this from the sell side is to keep your mouth shut if you are against the measures. Taking a public stance like this plays to the minority of people in this country who are either foreigners or progressives, but opens you up to have the whole thing thrown right back in your face the next time is a terrorist attack, because now, we've got it in writing that you opposed action that may have prevented said attack.* It's placing short-term gains ahead of long-term risks.
In any event, this is heading to the SCOTUS, where the advantage goes to Trump. One would hope they uphold the temporary ban and that Trump follows up with a more comprehensive approach a few months down the road. Specifically, one that establishes bans on known terrorism sponsors like the current ban does, but also establishes quotas from different regions that will have the effect of halting or reversing current demographic trends.
*Perception is what matters here, not "reality."