Cash isn't quite as bad because it's less practical, but yes both are primarily useful for crime and antisocial activity. I would be suspicious of someone who paid a large bill in cash (or used gold, or bricks of drugs); wouldn't you?
I'm not answering your question as written because I disagree with the concept of cash and "bricks of drugs" as being equally suspicious.
Being suspicious of cash is very dangerous. Historically, the poor rely on cash far more than the rich, so if we start demonizing it, really you're demonizing the poor. Politicians know this and often exploit it to help their rich friends.
Bitcoin has the capability to be the great equalizer, not just across economic bands but also across country borders. Your fear of it seems unfounded, though the paranoid part of me does wonder if you work for Visa or some other financial institution.
That'd be a proof-of-stake coin. They exist. You're thinking of in proportion to their percentage of the network mining power. Which for a pool (cartel?) can be sizable.
But that it is more akin to controlling the post-office than controlling the bank. People can be inconvenienced but not stolen from (except in certain cases with confederates of the post-master) and those can be guarded against more easily than avoiding phishing email from "your bank".
> those can be guarded against more easily than avoiding phishing email from "your bank".
What risk measure are you using there, and what ease measure? E.g. waiting for 6 blocks for transactions to settle (best practice AIUI) would be a serious inconvenience when e.g. paying at a restaurant.
You expect a restaurant customer to perform a double-spend for their dinner bill? One confirmation is enough for, roughly, anything worth less than the block reward. When you sell luxury cars you may want to wait a bit longer.
Mostly, attacks on the protocol itself (instead of your android wallet, etc) require significant mining effort and usually waste it effort by making the block incompatible with the global network (the double spend). When the cost of the item, divided by the number of blocks the merchant waits, is greater than the block reward divided by your likelihood of finding enough consecutive blocks to cheat - it may be worth it to try.
Specifically for food - you're supposed to mention coupons and traveller's cheques at the start of the meal, giving the restaurant time to prepare. The confirmation time (one, or maybe two blocks) could be handled the same way - pay a bit early.