I'm afraid it has everything to do with democracy.
We have rules concerning elections for a reason. The reasons are in the main to prevent the manipulation of the vote.
You may well not be susceptible to subliminal persuasion on this particular issue but others who do not feel so strongly may well be. The Co's who are dealing in this type of Psycho Campaign are not within the UK and so are beyond the reach of the UK Electoral Commission who have sought with little success to investigate this issue.
The process of winning elections is about influencing those who are open to be influenced, 'the floating voter' term is often used. Psycho campaigning recognises and targets those voters through the gathering of data from all available sources and then uses that data to tailor a programme of persuasion without the voter ever knowing what is happening.
A crude example might be used on a parent by associating child abuse with a political party. I believe the methods are much more sophisticated than this but you get my drift.
This type of thing is reprehensible whoever is gaining or losing by it.
Is this fundamentally different to the way that political parties "bombard" voters (by all methods) in marginal constituencies?