Materia 101 3d printer is open source child of Arduino and Sharebot

Arduino and Sharebot, both based in Italy, partnered up to develop and deliver new open source printer: the Materia 101. Arudino is a major major player in open source hardware community and their name on a 3d machine will draw some major attention.

• Printing technology: Fused Filament Fabrication
• Printing area: 140 x 100 x 100 mm +/- 5mm
• X and Y theorical resolution position: 0,06 mm
• Z resolution: 0.0025 mm
• Extrusion diameter: 0.35 mm
• Filament diameter: 1.75 mm
• Optimal temperatures with PLA: 200-230°
• Tested and supported filaments: PLA
• Unsupported but tested filaments: Cristal Flex, PLA Thermosense, Thermoplastic Polyuretane
• (TPU), PET, PLA Sand, PLA Flex
• External dimensions: 310 x 330 x 350 mm
• Weight: 10 kg
• Usage: 65 watt
• Electronical board: Official Arduino Mega 2560 with Open Source Marlin Firmware
• LCD display 20 x 4 with encoder menu
• Preloaded with PLA printing presets
• Extruder block with filament pressure regulation
• Price: under 600 euros ($755) in kit form, and under 700 euros ($883) assembled.

I don't understand why is the print volume so small? Why? 

Materia 101 on official Arduino blog: http://blog.arduino.cc/2014/09/30/arduino-materia-101/

Here is video of it in Italian: