I eat at a LOT of restaurants (burbs and the city). I can't remember the last I encountered a server I'd call "entitled." Most servers are humble, hardworking people.

There are more reasons than those listed in this article as to why an auto grat may be applied to large parties. In most situations the server would not walk away with the mentioned $54 on the party of six with a total bill of $300. In most cases the server is responsible for tipping out all other support staff, that can include kitchen staff, host, bartender and bussers. The amount a server tips out is usually based on total sales and not total tips made from the evening. These tip outs can add up to ten percent of a servers sales, so in this case the server will be tipping out $30 dollars regardless of what tip was left. The server made $24 off this table more than likely and that's great especially if the table only took an hour to eat as the article explains.
More often than not large parties take longer than smaller parties from the time they sit to the time they leave. (Think about any time you have dined out with a large party and sat waiting at your table for 10-30 min for all the members of that party to arrive or stayed at your table talking for 20 min after the bill was payed). If a server has an 8 table section for an evening and 4 of those tables are put together to accommodate a 12 top, the amount of tables they can turn in an evening goes down. Sometimes just the act of being a large table can automatically mean that the server whose section you have been sat in will make less that evening. Imagine that the 12 top only leaves a 10 percent tip. The server made no tips from that table and was limited in the amount of tables they could turn in the evening. Imagine the 12 top leaves less than 10 percent, the server would than in effect be paying money out their own pocket to have served the large party in order to cover the tip out owed to other staff based on the total sales.
If you go out to eat, have a terrible experience from start to finish and find an auto grat on the bill that you feel is unreasonable, by all means explain it to the server. Provided you have had a good (to hopefully) great dining experience keep in mind all the above mentioned as reasons why the auto gratuity may be applied to your bill. The only thing as equally bad as an entitled server is an entitled customer.