There can't possibly be any secular aspects of Christmas or Easter to celebrate, unless the secular have adopted and adapted them from the religious celebrations they are. If the non-religious have adopted a religious festival, they cannot be heard to complain that it has been forced down their throat.
Saint Valentine's Day has been associated with the celebration of love since Chaucer's time at least (per wikipedia), and there is no suggestion that it was introduced by mediaeval businesses to boost sales. There may be a question about which St Valentine Chaucer was referring to, but all saints are religious people, so I contend that the festival had more to do with religion than business originally. Now, however, modern business "owns" St Valentine's Day and virtually owns Christmas. Chocolate producers are well on the way to taking over Easter. They are even introducing Christmas into non-Christian countries such as Japan, and that can be for no other reason than to take advantage of the Japanese gift-giving culture.
I'm sure the Chief Purchasers of the shops and supermarkets you patronise would be delighted to learn that you believe you make your buying choices unaffected by advertising or any other influence. I suggest you buy whatever those shops choose to make available to you, and even if you are immune to the advertising you are subjected to, they are not. They won't stock many goods that the producers aren't willing to promote, because rival items that are actively advertised will move off the shelves faster. Christmas and other religious festivals are the most important times for sales in nearly every kind of business there is, and only a fool would refuse to capitalise on it.
You say you have no problem with business making money out of religious festivals. If the boot was on the other foot, and you wanted to utilise whatever product or service a business provided for your own purposes, you would be made to pay a royalty based on how much use you would be making of it. What royalties does Wallmart pay to the Vatican?