Like Colwyn said, the folks who are in a precarious position are those with large amounts of lira in the bank or other lira investments, who, at some time in the immediate future may want to convert some of that lira into sterling (or euro or whatever). If you're in Turkey for the duration, then all you have to contend with is inflation eroding your capital.
I've seen (on other forums) folks saying that they don't care about the exchange rate as they're still getting 10%+ interest. All good until you realise that inflation is in double digits which kinda wipes out those gains, after the tax man has had his slice. My OH was working in Istanbul during the crazy times where a loaf of bread could change price between you picking it and paying for it, lets hope it doesn't get to that stage.
Short to medium term I don't think folks who own property have much to worry about (purely my opinion) from an economic perspective, unless they want to sell up. The problem then is that their perceived (sterling) value of their property is unlikely to be met. Of course there'll always be exceptions, but when the economy is in turmoil property prices tend to fall.
While I would urge caution to anyone considering purchasing a property in Turkey right now, if we hadn't sold Karagozler last year I wouldn't be overly concerned - that said, I'm still pleased that we did.
JF