The only less pleasant event of paying for your tickets in Bitcoin is that it will allow governments to spy on you due to how strict airport measures are. Every time you check in and out with your passport, they will be able to find out where you go, when you come back, etc. It's literally big brother is watching you. It might not really be a problem for most people, but I'm sure there are a lot that do mind this, and for that reason won't book anything with Bitcoin that requires passport checks. What if the government has a trigger that will require further inspection because your wallet (the one you paid your tickets from) has +$100,000 worth of coins they don't want you to take with you? It might seem like a semi fantasy scenario right now, but we aren't all that far away from these measures.
The amount of linking of data that goes on (without Bitcoin payment) is already huge. Governments know where all you have gone, how much money goes into your bank account, how much you have spent. They also know what websites you visit and what you have been searching for.
That said, I wouldn't want to pay for my tickets using bitcoins, precisely for the reasons you mentioned. Plus I do not want the headache of calculating capital gains for such events and reporting them.
