It's not a perception - it's the fucking reason!
We all know why shops started doing this, and it's not the horrible costs of paper till rolls. It's to harvest a massive number of email addresses. And that's proved by the fact that nobody asks you if you want to get junkmail when they ask for your email for a receipt - and the first email you get when you do is always a sort of welcome to you and why not have a look at our latest offers thing, and only then comes the email with the receipt. Usually followed by a voucher the next week - or just a general marketing email.
Which is why I only accept electronic receipts if I want the marketing. But all that marketing is still illegal, because they've asked for my email for a specific reason, then used it for marketing. I don't think I've ever been asked. Though I got an e-receipt from one of those gadget shops at Christmas, interested to see what offers I'd get, and they're the only one that didn't send me any junk email, just the receipt. So kudos to them.