Phukets combination of factors, not only airports..
A changing visitor demographic was never good for it, I have long argued that the single male traveller spent far more, in a much more direct benefit way.. The quality tourist spends 90% of thier money in thier luxury resort, the family tourists wanter round with a stroller and buy nothing but a wooden frog and a sarong, and the female travellers simply dont squander money getting hammered in bars with sluts in the same way. Thailand, and especially Phuket (and possibly Samui) where the trend is possibly the most noticeable, will regret that IMO. The only winners are those tiny % of the population that own major resorts and land owners leasing out to international chain stores.
Add in of course multiple coups, airport closures, and a gouge the tourist attitude and you dont want to alienate the very group that would put up with all that (the single male in search of girls).. Families simply wont just grin and bear it.
All that said I dont predict the demise of phuket, its been through so much and still grown. Good businesses will still trade (as long as thier initial investment wasnt too harsh) and prosper.. The weak hands will leave the table and the good should end up sitting with the pot.
Now more than ever tho, people should make the effort to make sure thier baht goes to businesses the respect them, provide the best service, and in general treat them with the respect a customer deserves. If poor service and those little tourist cheat tricks that so many businesses have used for so long are used, people need to make sure those are the businesses that leave the market.