You are not voting for your future husband or son-in-law; neither are you voting to see who qualifies to be your son's tutor.
Your personal likes and dislikes pales in comparison to voting for the Parliamentary system to function in the way it's designed to be. Spoiling your vote will do nothing to influence the debates in the Parliaments when unjust bills are tabled, unless, of course, you are "for" the status quo.
It used to be those "bo tak chek" old folks who think that come election it's a good chance that the people in power will knock on my doors and kowtow to me; it's a good chance for the ordinary folks to "feel a little power" over their lords.
For once every 5 years, the table is turned for 9 days when ordinary folks play the employer, and the people in power cower for their attention. Once the cheap thrills is over, the ordinary folks are back to being screwed - and they fucking deserved it !
In every election, you don't vote for an individual, his academic credentials or his career path. You vote for the proper functioning of the Parliamentary system; you vote for the policies; you vote for the parties whose policies you agree. This is something those bo tak chek old folks cannot understand because they have no idea WTF is Westminster Parliamentary System.