It's like everything else. No one likes paying anything more than they have to !
My point is if truly desperate you'd absorb a private rent or share. Other decision-makers will unfortunately see it that way also.
There is most definitely a void and it is difficult for first time single buyers who play buy the rules, but that isn't going to change anytime soon.
Being a landlord is a business and I'm not sure if landlords can be completely described as greedy since it can be a high risk business if you end up getting squatters or the place trashed. Yields have always been higher in Lerwick than elsewhere in Scotland but there is an opportunity to haggle, especially if you have longer term aspirations (noting new laws mean there is no fixed minimum term like 6 months or a year anymore, so longer term can make you more favorable to landlords). New laws also mean landlords can't suddenly hike prices up or turf you out for someone else during an oil boom.
Save a deposit, absorb a private rent if you have to for your own happiness (sharing will cut it in half or more), and skill up if possible until you can buy, would be my advice.