Fuck Tequipment. Fuck them hard with pineapples.
With that juvenile method of communications, I wouldn't blame them for ignoring you.
While the wording is not very appetizing, IMHO you should stop confusing cause and reaction.
Him using those words does not make him a bad guy here. He was wronged, he has right to be mad.
How you express it is different issue. You can call him vulgar, but do not pretend that means he is not right.
Everybody can be frustrated to the point of losing their temper.
And while you had good experience, there is other people that had bad one.
I personally like to hear bad experiences too. Like he told you, with other vendor he also had complaint that they handled valiantly. All praises.
While the one he has colorfully complained about sent him used equipment as new and then tried to pretend it ain't so.
Other time he had to make a legal action.. To other person they lied about delivery schedule..
So that is a vendor to be vigilant about. Good to know.
And for good/bad posts ratio, that is somewhat debatable. Sometimes it is like you say, and sometimes not.
People usually write in length (and hold grudge) when something really bad happens. But smaller anomalies, or those that get sorted out before they get really mad nobody will bother to spend time to write. But those are real problems that some other vendors don't have and there it is really smooth. So in real life you would be better of with other vendor. Not a big deal, just easier.