There are two sides always so let me share my experience on the customers and restaurant staff/service
Types of restaurant customers:
1) The ones who do not bother about their kids messing the place, they are hooked on to the phones or busy discussing something. There was one incident when kids were just running around and they hit a big pot that had few plants and dropped it on the floor. No apologies or anything, the mom came and just shouted the names of the kids and asked them to go sit quietly. The staff obviously had to clean the mess.
2) The ones who own the responsibility of feeding others on the table. I hate these kind of people, especially when they are in large group; there will be one uncle or aunty who starts bossing around and act strict in terms of who should eat what. I mean can't they do these at home ?
3) The overly sanskari ones. Especially when they are abroad. I was having a quick lunch at one of the Malls in Sydney on a Sunday - They have a nice food court and large seating area which is busy than normal.
So this indian family with two kids came in loudly (over excited lady screams "arey chachuuuu" and was loud enough that a train will stop

) and they all greet a slightly older couple who were seated earlier. Now the mom wants her kids to bow and touch the feet of the older couple. Both kids were slightly on the heavier side, reluctantly they tried to bend and touch the feet of elders. In that process the backside of one of the kid touches the table behind. On that table there was a family sitting with big glasses of coca cola and fries etc. The bending and touching action was strong enough to dislodge the glass from the table and floor is now enjoying the cola !.
No Sorry, no apologies, they just look around and noticed the attention they were receiving, they just walked away quickly to another direction - maybe embarrassed but isn't it basic decency to apologise and also offer help to clean the mess ? And can't they check surroundings before they do these sanskari offerings ?? Won't be surprised is such a scene comes in one of the movie or comedy show.
4) The confused and last minute change wale. I have noticed this multiple times during office outings and with friends. They take the menu, memorizes the menu but decides to pick on roti + Paneer butter masala combination. The order is taken and after few minutes they again call the staff and asks to change the earlier order with another item. Some restaurants oblige and some do not. Such denial from staff made few colleagues angry and they feel its okay to shout and scream, display high handedness. After all customer is the king, isnt it ? And no laws and rules to tackle rudeness/anger
5) Then the drunk wale. The most dangerous but sometimes funny too. Was attending a corporate dinner party at one of the leading 5 start hotels in Hyderabad, the staff gave enough notice that the restaurant will close at 11.30pm and requested final orders around 10.55pm. No one reacted or responded to the message but at 11.25pm they suddenly decided to order a few more. And when drunk, people just do what they do.
One of the team member had a special request - "Curd rice" Another wanted a few more pegs, was also trying to impress the onsite staff member about his influence but when the staff denied all the requests it obviously offended the team members. One tried picking up a fight with the hotel staff and retracted when he saw the well built security staff. Another picks the mobile and shot an email to the admin staff asking them not to pay the bill as the "food and service was not up to the mark" (It was a bill to company mode) and copied all the attendees requesting their support ! He also said that this particular hotel should be delisted from the choice or restaurants for corporate events. I do not think anyone cared !
Types of Hotel Staff and experience dealing with them:
1) I often wonder why you need so many staff members even in a restaurant that is having 1500 - 2000 sft dining area. Is it a norm ? I often see there are couple of supervisors/managers to take orders from customer tables assigned to them.
Then there are junior staff members who job is to just come, put the cutlery etc on the table. Another junior staff will be responsible for bringing and placing the food on the table. The supervisor guy comes running and asks the staff member to serve food - And he just starts serving. He is not bothered about who ordered what. Now the customers on the table will have to direct who needs Veg, Non-veg etc. The supervisor is nowhere to be seen leaving the clueless staff member in front of customers.
2) Visited an upmarket restaurant that's famous for their varieties of pulao and biriyani. They show the menu and highlights Chef special. I ordered it and after 10 minutes he comes back saying its not available

Now i ask for another dish - he goes back to the kitchen, checks and then comes back saying No again. Shouldn't the staff member taking orders be aware of what is available in the kitchen ? Eventually i ate what they had but not the best experience to go through.
3) The other irritating breed of hotel staff are the ones who will keep coming every few minutes asking if i need another dish. Even after requesting them not to disturb and that i will order when i am ready for the next, they do not bother. These might be training issues but definitely irritating.
4) The ones who cant speak anything due to fear or low confidence. I do not know why hotels employ such staff. I often face this problem and i do not know what to do. There was a time when i felt really sad seeing a young guy dressed up but can't read or write. He is obviously afraid to speak though he understands Hindi well. He is coming from a village that's far away from Hyderabad and close to the infamous Maoist controlled area ! I ordered caramel custard and he could not figure out what i said. So i gently took the menu and pointed my finger to the line which listed the item. The poor chap kept his finger on the same line, took the menu inside the kitchen. Eventually they served the right dish but it is not the right thing to do.