I'm not fussed if 16-year-olds get to vote or not, but I do object to this nonsensical position that they are somehow not mature enough to form a balanced opinion about whom to vote for -- which, in any case, invariably means that "the impressionable *** will just vote for lefty parties and not the Tories like sensible chaps would". It's simultaneously insulting to youngsters and arrogant of adults. Not to mention the rather sad implication that people should be denied a vote because you aren't happy about who they'd vote for.
Voting should be linked to the definition of adulthood. At the moment that's 18 in most legal senses. Maybe it will change to 16 at some point. So what?
For the moment, at least, this is purely academic. It seems right that the voting age should be lowered to 16 only on its own merits, or not, if it comes up as part of a general package of election reforms, rather than as an amendment to an early election bill. As I understand it, that amendment has not been selected for debate.