Well, Sending someone a merit is someone's personal choice. You can't force someone to give it nor that someone can force you to give a merit. Infact i can give you one right now yet i choose not to.
That does change the situation? Obviously not. There is no point in hitting lauda or that atriz for a freedom that the system gives to its user. If you are really butt hurt then I suggest to instead improve. Fight back in a more professional way
Regards,
But why do people are people that are selling them getting tagged with negative trust then?

Here is a kind of double standard taking place.
Selling is not allowed. There is no double standard.
I thought that selling of merit was only disallowed for sources.
Good point. I don't think that was clarified. Therefore, you can safely assume that it applies to everyone (buying merit is just outright dishonest, and very similar to buying trust).
I thought that initially Theymos had written something in the OP of the merit announcement thread about merit sources being prohibited from selling merit, but he seems to have reworded it and removed such language, but i am sure that he said it.
https://bitcointalk.org/index.php?topic=2818350.msg28856522#msg28856522Oh I found this language in the merit page for merit sources:
>>>>>>You are a merit source. The next XXX merit you spend will come from your source rather than your sMerit balance. Merit spent from your source will come back in 30 days. Unused source merit is wasted. It is not allowed for merit sources to sell their merit.<<<<<<
I think that the closest language regarding regular members trading merits was this:
Merit sales, transfers to aliases, back-and-forth trading, etc. are not much of an issue. All illegitimate merit will decay, and will account for a tiny and very expensive fraction of the total merit economy. It's basically a rounding error; fight it where convenient, but waste no sleep over it.
I think that actmyname has been too hasty with some of his negatives, but I haven't had time to look carefully enough into it to justify making forceful changes. I did exclude actmyname from my trust list, so another DT1 could remove him from the default trust network by doing the same.
From this post:
https://bitcointalk.org/index.php?topic=2818350.msg29540717#msg29540717