Maybe a large upswing in spoiled ballots would be taken seriously but that's only after the fact and by that point the election is over and done with, those who have voted for a party get their votes counted and the winner is chosen from them.
I'm not arguing with you about whether deliberately spoiled ballots should count for something or that there should be a "none of the above" option, I'm explaining whey they don't count at present (or at least not in the way that some people think they do). The best you're likely to get is the person totting up the ballots has an unofficial count of the obviously intentionally spoiled votes and maybe that your inventive and heartfelt questioning of the local candidates parentage raises a smile.
It's a valid choice of course but in terms of how it is counted at present in the UK there's no distinction between the person who can't fill it out correctly and the person who chooses not to fill it out correctly. The recording doesn't factor in the intention of the voter, the end result is the same, it's a vote that is not valid so it gets bundled in with the voter who hasn't managed to follow instructions.