Here are some that I can think of on the top of my head:

• It's volatility in price(currently). Hence holding your funds entirely on bitcoin is a huge risk despite the advantages.
• Very unsafe for careless and technologically-illiterate people. Logging in to a phishing link? Say goodbye to your exchange's funds. Forgot to list down your wallet's seed? Say goodbye to you wallet's funds.
• Unable to operate offline or non-electronically. This is a downside on more on the 3rd world countries, whereas most poor people can't even afford smartphones or any device that can hold bitcoin.
• Not-so-good transaction fees and time. Transaction fees and times are definitely alot better now compared to months ago, but I still remember the days when txs were almost instant, with very very low fees.
• My personal opinion: The name "bitcoin". I personally think it sounds like something a person involved in pyramid schemes and Ponzi scams would use.