A few questions:
1) Do the polls promptly close at 10pm or do they close when the queue disappears?
By law, you must be holding a ballot paper before 10pm in order to be allowed to vote. A few of the polling stations went out and handed ballots to people in the queue before ten and then kept the polls open long enough for them to vote, but there were a number of places where several hundred people were turned away.
2) Does British law provide that employers must allow citizens to vote? (US law does this)
Nope.
3) Isn't four hours enough time for you to exercise the Right to Vote?
People in Iraq certainly endure worse than you in order to vote, so I think you're being a bit ridiculous with your complaints. In my area, in the US, the polls are open from 7am-7pm. I have leeway either way of getting to the polls on election day; however, even with 12 hours most Americans are apathetic like yourself.
There's really no need to be an arse about this.
People weren't expecting the incredibly long queues because there hasn't previously been a problem with that. The UK generally has a pretty good voter turn-out. The last elections, turn-out was lower. For some reason, some of the busier centres weren't sufficiently prepared for the (anticipated) volume of people this time.
As a result, some people didn't get to exercise their right to vote. There are reports of people queuing from 8 and not getting to vote. That's not something one would have expected from experience.
There was a cock up. Which is wrong, and a genuine cause for complaint. There's absolutely no call for shooting everyone who didn't get to vote down as lazy.
Maybe some of them are single-parents working long shifts who then had to get the kids fed and wait for the minder before they could get out to vote. Maybe some of them were students who skived off in the pub until a few hours before the polls closed. Either way, long queues due to understaffed polling stations are first and foremost a reflection on the preparations of the councils, not on the electorate.
(Seriously, have you met the British? If they were told to queue from three in the morning, they'd do it.)