Doug, Kalmbach bought GR many years ago, keeping Marc on as editor, so--no--they didn't buy it to kill it. They carried it through what was really the golden age of the hobby in the late 1990s - early 2000s. Print media in general have had a really hard go of things in the digital age, though, and that started gnawing at the magazine's profitability quite some time ago. The big mail-order shops stopped taking out 4-6 page ads, instead just taking out 1-page ads pointing to their web sites. That's a HUGE chunk of revenue evaporated virtually overnight.
What happens, though, is you get a downward spiral. Revenue goes down, costs go up, so you have to cut page count. When you cut page count, you cut content, you lose readers, ad rates fall, revenue falls further, pages must be cut further. Again, this is happening across the industry, not just at GR. Kalmbach did a serious belt-tightening a few years ago when they let Marc go and brought all production in house. The in-house staff wore multiple hats and worked on multiple magazines, dividing their attention. When that happens, quality suffers. When quality suffers, you lose more readers. It was only a matter of time.
Having said that, this came as a surprise to all of us who worked on the magazine. Hal (the editor) was making long-term content plans. I had just finished my next column and got my "due dates" for the next year's worth of magazines. We were expecting to continue going forward. I don't think any of us had delusions things weren't hanging on by a thread, but we didn't know the thread was about to be so abruptly cut.
It will be interesting to see what comes next. Nature abhors a vacuum.