This does not mean they would pay more for advertising.
There were markets - specifically classifieds and listings - where buyers did very much want to pay for ads. But those were very specialised, and it's debatable whether a personal sales listing (dating notice, pet offer, etc) is in any way similar to a corporate ad.
Realistically, absolutely no one was going to pay for a version of Computer Shopper which had zero independent content and was just a giant ad directory.
Just as absolutely no one [1] will pay money to view a movie presentation made entirely of ads. Or watch a TV channel [2]. Or listen to a radio stream. Or view a web site.
[1] It's possible there are a few individuals who would do this, but clearly not enough to support a viable market.
[2] You might think Home Shopping Network, but HSN is free to air not pay to view.
So you haven't touched industrial magazines. Explains everything.
Pre-internet, the way that you can actually get information in a field is to have a publisher collect advertisements from related companies and send it to you. That's beyond "hate", it's the opposite: you are interested in any offerings but are not sure of who will you go to.