The others have made good points. Let me ask you a couple of questions, Ms Learner: 

1. Why do you send a “friend request” instead of actually starting a conversation with a personalized message? 

2. By the way, if someone came up to you on the street and said “let’s be friends”, how would you react?

Yes, I decline "friend requests" from people who don't even bother to change the standard template italki inserts in the message when you send a request. Often, they don't even speak any of my target languages. If they do speak one of my target languages, they haven't read my profile, especially the part where I say that I don't reply to generic messages. I feel no guilt in declining such requests from people about whom I know nothing, and who are probably sending messages to the first people who pop up in their search. The least people should do is read the user profile. If that's too time-consuming, I'm not interested. Besides, if people don't have time to read one page, I do wonder how they'll have time for a language exchange or even message exchange.

I regretted making myself visible on the language search, because of a flood of generic requests and spammers/scammers. It's frustrating and exhausting. So, I turned it off. People can find me through community activity and get in touch that way if they want. It's more likely to be productive and stimulating.