You can purchase real estate for Bitcoin, using sites such as Bitpremier and there is nothing unusual about it. But all these sites use a third party payment processor to immediately convert your coins to fiat currency. You are paying the amount in Bitcoin, but the prices are pegged in either United States Dollar or Euro and in the end the individual who is selling the property will be receiving the money in fiat. Due to the volatility associated with Bitcoin, it is not practical to accept it directly for such transactions.
That's the real issue. Why accept Bitcoin if you're going to quickly convert it to Fiat? If Bitcoin wants to be used as a real currency for day-to-day transactions, people and mainstream businesses need to "hodl" it instead of converting it to another currency. Of course, this is largely attributed to Bitcoin's volatility in price across the market. As long as Bitcoin fluctuates in price, businesses and merchants will have no choice but to convert BTC into Fiat for financial stability.
I'd be surprised to see real estate companies accepting Bitcoin directly without having to rely on a payment processor for immediate Fiat conversion. But so far, nothing like this exists yet. I believe that the most trustworthy way to buy real estate is through BitPay. After all, it's one of the most trusted payment processors for BTC to Fiat transactions in the mainstream world. I've seen many shady companies accepting Bitcoin for payment which are not widely recognized worldwide. To my knowledge, renowned real estate companies in the US haven't accepted Bitcoin yet. So it'll take a long time before someone will be able to buy real estate confidently with their Bitcoin.
Nonetheless, time will tell us if accepting Bitcoin or any other cryptocurrency for real estate will be worthwhile. As long as the crypto/Blockchain space remains widely unregulated, mainstream real estate companies will continue to rely on Fiat payments within the mainstream world. Just my thoughts