While a success in terms of promotion, however, Gemini is showing signs it is struggling to appeal to bitcoin's active trading community.
Not so sure I agree with this statement. The doors only opened a week ago and at this stage I do not think one can say that they are struggling. Just because there was no large influx of traders from day one does not mean that they are struggling.
I'm sure that the numbers will increase as many may be sitting on the sidelines for now to see how the launch went and to see how things look before making a switch. If the numbers are still low in say a month or two then maybe one can start suggesting that they are struggling but at this stage of the game its way too early to make this kind of judgement.
The following is however something that I agree will have an effect, especially so on retail traders...
They argue that Gemini's pricing model, charging both buyers and sellers on each trade, while potentially attractive to infrequent institutional traders, could prove an issue that will drive away retail traders, a demographic they argue is essential for building liquidity.