I've seen this argument several times since rowberry got the American record. But really rowberry isn't any more competitive than Simpson but no one is saying rowberry should switch events. Is it because the 1500 is her only event or do you think really think she has that much better of a chance to medal?
The difference with Rowberry is that I don't think that she could be more competitive at another event-nobody thinks she could. I do believe that Jenny has a better chance to medal in the steeple, if only because her chances at 1500 are near zero, or just a bit better if Dibaba isn't there for whatever reason.
As for the more money in 1500 argument, that may be the case, I don't know. If she was an east African, I could see that as the main motivating factor, but it seems to me that well-off westerners are less likely to be swayed by that.