Earlier quoted context omitted.
Your money is exactly as secure as your private keys, and if they are stolen there is basically no prospect of getting it back. "Be your own bank" implies "be your own security division", which very few people are qualified to do.
If I leave cash on the street should I expect it to be safe? Is that a deep security issue? You implied there were deep fundamental flaws in BTC security, but your response shows nothing of the sort. Your 'deep flaw' is 'you have to protect your private keys'. You are describing a UX flaw, and I would agree with that. Objectively, you have exposed no 'deep security issues'.
Bitcoin's non-physical nature (as compared to paper and coin currencies), I think, makes it more of a metaphor to a bank account or debit/credit card than a currency. This likely is a UX flaw, as you state, but it's a pretty big flaw.
And credit cards, in most jurisdictions, have lots of protections against theft and fraud, as well as consumer protections like chargebacks and transactions are reversible, of course.