As I understand that you are the editor of more than one magazine your opinions are interesting. I am a little surprised that you view newsagent sales less enthusiastically. If Smiths, for example, don't sell many copies they will remove the magazine from the stock lists of the stores that stock it. Model Boats is not available in all their stores now and could be removed from more/all. If that happens then surely it stops new readers from picking a copy up, thinking it worthwhile & subscribing? The magazine might make more money in the short term if everybody subscribed but longer term?????????????
Only one magazine, but I work on others.
It's a balancing act far more nuanced than you make out. Yes, it's good to be on Smiths shelves, but they aren't the only place selling. In many ways, supermarkets are as, if not more, important. People don't tend to stand and read the entire mag then put the mangled copy back, and it's a small addition to the overall bill when chucked in a trolley.
There is also this thing called the Internet for discovering publications, hence the push via social media for all magazines.
There is a model for all this - the US and Canada. Neither have newsagents in the way we do, but they still sell magazines. A very small number appear on the shelves of a supermarket or drug store, but nothing like the selection we see even in a UK supermarket. Hobby mags still sell despite this.
Fortunately, all this isn't my problem. There are people paid far more than me negotiating with the distribution chain. However, if you look at the efforts made by every magazine to get subs, it tells you a lot about where the money is and those decisions are made bu people who really know the market. You might call it short term, but a magazine that has gone bust isn't on anyone's shelves.