Is it actually being abused, though?
Personally as I said I'd like to be able to vote online. If it was offered as an option only to holders of current biometric passports and smartphones capable of reading one via NFC*, it could be done pretty securely, too - certainly much more securely** than a postal vote. The tech was developed for the "application for leave to remain" app for EU citizens.
Obviously those without biometric passports and/or smartphones could still vote traditionally if they preferred. But I bet uptake would be VERY high - it might even improve turnouts.
* Scan the passport, verify the biometrics using the phone camera, and send some sort of encrypted report of veracity back.
** Remember, any replacement system just needs to be "at least as secure as the present system", it doesn't have to be perfect. As I like to, I remind posters of my proposal for a system for e-ticketing on here a while back, which was rubbished as being too insecure, but was, it turns out, very close to the one that was actually implemented - indeed, in some ways my design was more secure than the one that was implemented.