OPTUS has used the word yes as a marketing slogan for 25 years.
Obviously the use of the company's name is much more concise than "Australia's second largest Telco".
Long before the word yes became so political, the word was simply a term of positive affirmation and/or agreement. No wonder, 25 years ago, Optus' chose yese as its marketing slogan.
Whenever possible, most people prefer to be positive rather than negative.
As the Optus slogan has been retained since 1992 it must have been deemed successful. It seems in Australia's current political climate, yes voters are portrayed as positive, progressive and loving whilst the very opposite is depicted of those who vote no.
Don't buy the marketing.
A no voter can be very positive and loving towards those with whom they disagree on such an important issue as same sex marriage. To disagree and vote no is not to hate.
To disagree is not to be a bigot nor to have a phobia (although some may).
If the survey was framed differently, a yes vote for traditional marriage would have been possible.
Yet, it is what it is and a negative no vote is necessary to vote yes for traditional marriage.