Why do people mark a question to be closed without any note/explanation?
There was an explanation from Chris S, that you even commented on yourself. If you read the links in Chris's comment, you'll see that a "shopping" question is basically any question where someone gives a list of requirements and says "Find me a product".
I do not think that any (free script or product) thing like I am asking about exists but before coding what I want by myself I asked here. What is bad about it?
The reason we don't allow these questions is mainly because whilst any given answer might be correct right now, it will be wrong in 6 months. Maybe there are new products on the market. Maybe the answers you get are no longer maintained/for sale.
Additionally, they tend to show a lack of respect for your peers on the site. We realise that this is of course not intentional, but ut's basically like saying "I can't be bothered researching this myself, so, do it for me". This is fairly common, and even yours truly has done thiseven yours truly has done this in the past. And it got closed, after someone flagged it.