With regards to (4) not sure if there is an argument for tipping being racist, but I know there is a strong one for it being quite sexist. I have a few female friends who work as servers, and a large portion of their job involves flirting with customers.
With regards to (5) a bottle of wine or scotch isn't really the same thing as restaurant tips. You aren't expected to give them every time, and they aren't a part of how they make their living.
With regards to (5b) "tipout" policies seem to be a source of lots of abuse among the places my friends have worked. They are inconsistent, often mean low tipping tables _cost_ them money, and can be a way for upper management to siphon money away from servers and into their own pockets.
4) I think many commenters forget that service is sales. Flirting is common to make a sale and you will see it across all industries.
5) Strawman. This is about tips in all industries as suggested by the writer. People in sales rely on perks in any form, it is definitely factored into whether they take one sales job over another.
5b) I think is a misconception, as stated management does not participate in tipout for this reason.
4) I guess I'd prefer restaurants where the servers were incentivized to be servers not sales people. Certainly that is the way most places try to present their service staff to the customers. When you have to flirt to keep your job, or to keep your job financially viable, that seems... exploitive. Sure, if you want to use flirtation to make a little bit more than your peers, that's on you.
5) the servers I know make a LARGE portion of their money via tips (off the top of my head I'd guess 60-70%). I would be shocked if any sales position had perks that rivalled that ratio.
5b) It's possible you are right. I'm vague on the details, but I know my server friends have lots of complaints related to the fairness of tipouts. I suspect the inconsistent way that tipouts are done means some places _will_ tipout management or other non-server/host/cook positions.
Service is not like sales at all. I'm an electrical engineer, I deal with salespeople ("business development managers") from my employer's suppliers every day. They are professionals, selling complex products to other professionals for substantial salaries + commission. I assure you that people do not flirt while describing the properties of the $1 million STATCOM they are selling.
In most manufacturing or construction industries, salespeople send gifts (on their employer's dollar, not their own) to their regular customers, not the other way around. And that's a professional courtesy, not a way to make a living. I'm talking about sending a box of chocolates to the purchasing manager who does seven figures of business with you annually.
In many restaurants (i.e. family restaurants, chains) the server will absolutely not flirt with you. However, in many restaurants that is part of the expected atmosphere. It is even possible to get a steak at a strip club. Someone has a want and someone else chooses to provide the service. This is the free market.
Almost every restaurant/service runs a "comp tab", servers/bartenders/managers expect to give away a certain amount of goods to regulars and other good customers. Many sales jobs are 100% commission, which is priced into the sale. Tipping just exposes that commission to the customer. In any sale, sometimes commission has to be sacrificed for a difficult customer. The service industry is no different.
With regards to (5) a bottle of wine or scotch isn't really the same thing as restaurant tips. You aren't expected to give them every time, and they aren't a part of how they make their living.
With regards to (5b) "tipout" policies seem to be a source of lots of abuse among the places my friends have worked. They are inconsistent, often mean low tipping tables _cost_ them money, and can be a way for upper management to siphon money away from servers and into their own pockets.