The mobile apps don't allow customization. Once a socially or even business savvy networker learns this.. then yeah, customize. My latest set of LI 'rules' highlighted some of the responses I get when I take the time to follow up to these generic invites, to ask how we know each other and why we should connect (or friend on FB). I share your frustrations, esp. when I get those "I want to send you an ocean of love" requests (yes, on LinkedIn.. not kidding). 

You're right - and the people who need to read these kind of tips and tricks posts don't. Just because you can attach 34 pictures to one email that doesn't mean you should; some people don't know (or care) that there are more technically savvy and frankly, digitally courteous ways to share all those pictures. Like anything else, there's a learning curve and we need to take the time to think about what we do - online and off. FWIW.