Does technology give people an excuse to be rude?

I'm trying to make plans for something invovlving someone so I e-mail them (I fully admit to having an aversion to the telephone as all previous call centre empoyees have. I think it should be classified as a documented metal illness). Some people, who must check their e-mail at 5 min intervals respond so quickly I'm surprised they had time to read it. Others get back to me in a day or two. Then there are the people that 50%-75% of e-mails and telephone calls I send, do not respond. These are the people I am now about to muse about....
If you are not interested please just tell me. I know lots of people don't want to spend time with me. That's okay I'm used to it, but it's rude to not fucking respond. I'd rather hear/read "piss off, I hate you, never try to contact me again or I'll call my lawyer" then no response. Just because it is now in electronic form it isn't any less rude not to respond then when your Aunt sent you an ugly sweater when you were 10 and you had to send a thank you card.
This also does not refer to the occasionally forgetting/ loosing of an e-mail or telephone message it happens. Also if you live in a cave that's okay too unless you don't respond to my carrier pigeon.

To all the people who respond in a timely fashion: Cheers, your mom taught you manners.