Hi,
you can edit template file, follow these instrutions:
- Go to Admin Panel -> Theme Manager
- Click on "Social Network" under Base theme
- on left select the file Events->view.cpt
- Click on Copy button and copy it in to Blue Theme
- Go to Admin Panel -> Theme Manager
- Click on Blue Theme
- on left select the file Events->view.cpt
- remove at line 68 this code to remove "Maybe"

<input type="radio" name="rsvp" value="3" <?php if (!empty($my_rsvp) && $my_rsvp['EventRsvp']['rsvp'] == 3) echo 'checked'; ?>> <?php echo __('Maybe')?>