I suppose they needed closure of some sort, as they didn't get the chance to say goodbye.
Whatever Benoit's reputation now, he was one of the most respected and well-liked wrestlers operating in the business, by peers and fans alike.
A lot of people close to him think that losing so many of his close friends in the last few years (especially Eddie Guerrero) contributed to his mental collapse. The steroids, painkillers and other drugs he was abusing certainly contributed.
I'm not making excuses. When all is said and done, he killed two people: his wife and son. And we know that Nancy had made a domestic violence complaint as far back as 2003, which suggests Chris had a dark side to his personality.
But certainly, many factors were at work with regard to what happened that weekend. The wrestlers who sent those texts just wanted to pay their condolences to the Chris Benoit they knew, I guess.