I'm using blockchain.info to send btc. Blockchain has a default fee when you send btc, I did not change it and it was saying with the fee provided it will take up to an hour. 2 days later still waiting. With two transactions stuck.

Can anyone explain why transactions would get stuck like that?

https://blockchain.info/tx/06054ef9368e1de58c8c32d1f9b8fff00b17f1a7befdfa2f71e9f6f710c05401 https://blockchain.info/tx/ee4d9ba8edeb2704c68a7f9161fc040b066c218bc87f6ff2cb3ee33a2ad51c9e

A lot of similar questions there, but no real explanation of why?