Presets make or break an instrument on several levels. First you must present what the instrument (particularly one of "novel" design) is capable of sonically and theoretically to move a buyer to part with $4k. Then, it's silly for a player to have to program from scratch the most commonly requested and desirable of timbres. Lastly, community is important to an instrument's success. Sound designers and players interacting together, on forums like ours devoted to the instrument, exchanging tips, tricks and patches. A popularly used instrument will also attract sound designers to offer patch collections.
Clearly presets are important to the designer as the C15 has user-definable banks, unlimited number of presets per bank, user editable infos per preset and the ability to search for presets based on name, tags and infos.