I think this is a complicated issue, and that people are upset over various aspects of it, such as the amount the modder actually gets, vs the amount kept by either Steam or Bethesda, or whoever.
I can see the point of people who don't want to pay for trash mods, as well, but I also see a lot of complaints that mods should only always be free. These complaints usually contain spectacular displays of ignorance as to just how much work and time people put into mods, especially the big ones. It concerns me just how many people have decided they are entitled the fruit of others' labor, without any regard to the feelings of the laborer in question.
This, IMO, is a very simple concept. If a modder wants to charge for his/her work, then it is the choice of the mod user whether or not to buy it. No one is going to come around and force people to use mods, and I'm certain there will continue to be free mods out there. I've bought the DLC. I didn't expect them to put hours and money into creating something just for me to demand it for free. Likewise, I'd consider buying a mod, if I thought it was worth the money. Simple business transaction. If someone wants to give me a mod, that's great too, but I can't imagine demanding that they sink their time and effort into it just because I say so.
As far as the 75/25 split, the modder has the same choice as the mod user. Is this worth it? As no one is being forced to use mods, no one is being forced to create them either. Simple choices.
The concept of paying for a mod that conflicts, or is shoddy, is another matter and adds another layer of complication. It certainly warrants discussion, however that's what there are endorsements and comments for. Paying for a mod doesn't absolve us of taking the responsibility to determine whether what we're buying will fit our needs, any more than paying for an appliance, which may or may not work, at Walmart. I don't know what steps they've taken for refund in the case of defect, but with the right approach, it can be rendered no more or less risky than any other purchase.
Bottom line? This is America. Don't like the price? Don't buy it. Just don't expect someone to give it to you, just because.