To be clear, I also avoid it when I can, and most of the time ad-free or open-source alternatives are available (in this case I have been using WinSCP). I dislike the mobile app ecosystem with its plethora of garbage, privacy invading apps; and I am glad that desktop apps usually aren't like that. But if a program is much better than its alternatives and the ads are not too annoying, I guess I don't mind supporting its development via ads. Being a poor person from a poor country, I couldn't afford purchasing the program or donating to it, so ads sound like one way of supporting a program I like so much (though my ad views are probably worthless for the same reason).
The only adware program I actually have is PotPlayer (the only thing that comes close is KMPlayer, which I used before; but it's originally built by the same developer and added ads even earlier). I think a few other programs I use had adware-bundled installers (e.g. JDownloader, CDisplayEx,...) but I had found adware-free installers. Even in the case of PotPlayer, it doesn't show ads, just an empty window (maybe again because I am in a poor country?) so I blocked the empty "ads" via hosts file. What's the point of annoying myself if that's not even supporting the developer? But if PotPlayer actually showed ads to me; assuming it didn't upload my private data and no comparable open-source/ad-free program emerged, I feel like I should be fine with it rarely showing some ads in the corner.