Hello Mister God (nice name :), first of all it's nothing personal,it's an open debate not targeting towards anyone but about a system, so no worries
First of all I do agree with you that logically the price should fluctuate as per the raw material's market price however it's not feasible for country like India as not only the restaurant but also the buyer (mostly) would not understand this system. Also, a buyer come to buy food with a budget in mind so giving him last minute surprise is not a good idea. I have been running a restaurant for last 2.5 years and have seen buyers getting dissapointed/turned away even for a small change in the price. So yes the restaurants take the losses on themselves during this peak time as in most cases it's a temporary phase and gets back to normal after a while. You must be aware in last few days tomato reached till 100/- per k.g. and is now at around 40/- and will be even lower soon (some...in fact most restaurants cover it by buying very low quality veg.). So you can't increase the price for such temporary phases. But again each restaurant increases the prices in particular intervals such as per year or so on.
As far as 420 thing is concern, just like any other industry, restaurant industry is not far away (being a restaurant owner I shouldn't say this but truth is truth). Best example we all know is the non veg food in which you are never sure whose meat (goat/buffalo/pig/dog) you are eating and that's why at some places you will get the non veg food even cheaper than the cost of meat only (not including other expenses). In case of veg food, one can cheat by buying low quality/unsold vegetables which cost much less. Before opening my Pure Veg. restaurant I wanted to start something in B2B non veg (as I can cook a bit) however after doing some market research, wherein I went to some local popular shops (whose sales is in lacs per day) and asked them if they would be interested in buying my products. You won't believe what response I got. I gave them the price based on quantity of mutton and they told me that they are selling it for half the price I am asking them to buy from me. Can you beat it? I clearly asked what are you selling? And they just smiled, looked at me and said 'why are you selling pure mutton?'. That day I decided not to go for non veg biz as I won't be able to earn as I won't be able to sell anything else instead of regular mutton/chicken, hence no profit.
I personally don't think so these FOPs are helping us in getting organized as such. In the world of internet you can find anything sitting at home without the help of these services and which will not put any burden on restaurants. Most people don't even know that their order is delivered by the restaurant or the FOP itself and they immediately start fighting with the restaurant upon getting the order delayed even if it's FOPs fault.
Frankly when I started, I wanted to make everything fresh upon receiving the order which is impossible with these FOPs who doesn't give enough time to make food. This is one of the reason that our restaurant is one of the most notorious restaurant in all FOPs backend for providing the food late and fighting with them as still we make around 50% fresh only (it's a big number believe me) and handover the food late.
All in all, untill you are one of the restaurant who is selling a chapati at Rs. 50/- or more, this system won't suit you. Small players like us (who are selling a chapati at Rs. 8/-) can't efford this luxury and working with them in a hope that slowly these customers would come directly.