2 days is good enough for the hairdresser, but not the sales presentation.
I can understand wanting to SET UP an event in the distant future (which you CAN do on an iDevice).
I am unclear why anyone would need an ALERT more than 48 hours prior to said event.
Let's say that I book a speaking engagement 6 months out (common for me). Although my presentations tend to follow a canned presentation, they are either political or economic in nature, meaning that the underlying facts change almost hourly. I also tailor my presentation to the group to whom I'm speaking. It's the same message, but delivered with different emphasis, based on the focus of the group.
Considering that it takes me a week to place recent events into context and adjust the presentation so that I spend more time on the group's interest and events change so quickly in the current political climate, it would be foolish for me to plan changes to my presentation 6 months out and give that 6 month old presentation, when the date arrived. At the same time, two days just doesn't cut it. I need a full week, including a two day safety margin.
The iOS Calendar app may be great for appointments with the hairdresser or remembering the date of the PTA meeting, but it is severely lacking for even ordinary business world needs. Salesmen, lawyers, board members, and many more have to budget their time and plan in advance of sales meetings, depositions, board meetings, etc. Two days just doesn't cut it. Neither does just two alerts.