There have been many discussions over the years related to voting and how various users feel the system could be improved.
Rather than Hijacking the daily giveaway discussion into a debate about voting and the design of the webpage, a discussion on the mechanics of voting and the semantics on what a thumbs up or down should indicate can be done here (in a central area).
As each days giveaway comment page remains visible (by default) for only 24 hours - it makes no sense for people to make suggestions that will be scattered across multiple giveaways - and reposting each day the same comments to recap what was said on previous days will only start to annoy everyone.
For starters here are three of the older topics - but I'm sure there are many more buried in the forums (or within topics) - which only illustrates why it makes sense to keep this discussion together.
Abuse of the yes/no positive/negative function
GOTD Evaluation System
Thumbs up Thumbs down
FAQ - Giveaway votes & Comment votes do not add up. Is it rigged?