Being irreversible of transaction is the product of being decentralized. A great feature that carries an issue. Though it is not considered as a big issue. Just proceed with caution and carry more cautions

The thing that I do not like about Bitcoin is in the aspect of transaction also. It would be very nice if Bitcoin transaction could be done within seconds. But since mining a block requires 10 minutes at minimum we should wait for minutes, hours, or even days before our transaction be confirmed. Waiting sucks Another thing is that, transactions can be prioritized based from the transaction fee added. Perhaps a FIFO protocol should be embedded to the Bitcoin network so that all transaction is fair. Last is the increasing required transaction fee. This issue is absurd. (Nothing to discuss here, you all get the idea, right?)