A typical B&M store tries to make anywhere from 20% to 300% margin and every middleman before them is trying to do the same. Nobody expects them to sell for their purchase price and people do know that they have a physical store to maintain and associated costs, but is it unrealistic to expect them to settle for a fair margin? They don't. They try their best to take advantage of the customer by creating monopolistic situations. And yeah, monopoly does not have to mean that you have to be the only seller selling the item. If you have two B&M stores selling an item and one is near your house and another is 30km away. You may be forced to buy from the store near your house even if they are selling for 20% higher price. Most business people hate competition and it is often easy for B&M stores to kill theirs competition.
Just to give an example, the cafeteria in our office building (not linked with our company) have 4 different caterers, As per their own descriptions, they supposedly sell South Indian, North Indian, Chinese and Western. Each of them sell a different style of food, but the only things they compete for how shitty the food is and only thing they do fairly equally is fleecing their customers. They fix the prices among themselves such that everybody is making a huge premium. If an item is too popular, they either remove it from the menu or increase the cost drastically so that others also get business. They don't let anybody else give them competition either inside the building or when they can help it, outside the building as well. This is also possible only because they are B&M operators.
But guess what, Online stores are no different. They are also businesses and they also act the same way when they have monopoly.
So what is the difference? Online stores cannot act like B&M stores because they usually almost always have competition to deal with and their business depends on their reputation. Whether the item you need is in your own city or in other city 200Km way or 2000km away or in a completely different country, a customer has the opportunity to evaluate the best deal and buy from any of them with the same amount of effort and the item would be delivered to their door step. That levels the playing field and breeds competition and competition is always good for the customer.
I don't care whether the online stores use predatory pricing strategies, but what they doing is offering value to the customer and competition to each other and to the B&M stores (which have been leeching of customers for a long time).
They cannot consort together to fleece the customer and even if a few of them try to group together, it won't last long because of the nature of their platform.
As long as there are a dozen different stores trying to give me options, as a customer, I don't really need to care how they are offering me the best price. Flipkart is running on 1300 crore loss because they were selling items at negative or zero margins. Is it really a customers problem if the B&M stores cannot keep up (leave alone make the insane margins they made earlier)?. Let them burn to the ground along with all the middlemen if that is what is going to happen. It doesn't also matter whether the online store is run by Indian's, Chinese or Americans or anybody else.
Shorter Summary: 
1. Every business whether online or offline is by its very nature targets to get the max money out of their customers. They are after all not doing it for charity.
2. B&M stores have the opportunity to create situations naturally or artificially where they have complete monopoly, remove choices for the customer thereby allowing them to fleece the customer while the online model almost always have better chances of ensuring competition by the very nature of the platform.
3. A customer doesn't really need to care how he is getting his best price. As long as there is competetion and he has options to choose, its fine for him. The reason B&M stores are losing out is simply because the customer is being offered better options by others. It is not a customers problem if the B&M stores have more operating costs or the other reasons they love to cite.
