1) confirmation time is too long
2) Increasing fees will be a problem
3) The fact it's really hard to find a place where you can buy something with bitcoins (I'm mostly talking about Europe)
4) When you buy something, you need 1 confirmation to avoid double spending ==> 1) & 3)
5) The fact there are a lot of scammers and ponzi, DD4BC, etc, shadow companies ruining bitcoin reputation.
6) The fact new users will probably try to install bitcoincore and won't be able to use bitcoin easily (that was my first experience - 3 days long trying to synchronize the whole thing)
1) merchants will accept zero conf when the malleability issue will be fixed, if they really want to avoid this issue for their customers
2) this is the only valid concern, but we are talking about a dinstant future were bitcoin is actually adopted
3)not a problem of bitcoin, but merchants and user base
4)again see point 1
5)not a problem of bitcoin, again, newbie need to not invest in such site, if they want to avoid scammers, and don't dl random stuff from the web
6)i think they are lazy to not do the proper research , becaus ethere is anything you need to know in bitcoin.org
1) Merchants can already accept zero conf transactions without any problem in the first place. Transaction malleability was never an issue since merchants would require the inputs to be confirmed. Double spend would not be able to happen without the original transaction changing it's TXID. Anyway, it has already been fixed by enforcing only low s value TXes.
2) If Bitcoin gets adopted, block size rises and miners don't have to enforce high fees anymore.
3) Yeah
4) Actually, double spending is always possible with every transaction if there is a massive block re-org or a 51% attack. If 51% attack happens, your TX needs to be behind a checkpoint for it to not get reversed no matter how long the attacker is in control.
5) There are thousands of scams on fiat too, phone scam etc. Does it ruin fiat? No.
6) Why Bitcoin Core? SPV clients are usually enough for an average joe. Synchronization is much faster now.