1) it would falsely claim updates were required, when 32bit had updates that were not released on 64bit
2) it attempts to downgrade 64bit apps to 32bit ones
I show a screenshot of Irfanview 64 being incorrectly re-installed with a 32bit version. At times the 32 & 64 bit versions of apps should co-exist, plugins often weren't ported to 64bits, but 32bit is inherently less secure than 64 due to address space limitations so favouring Win32 is a deviant habit.
I was amazed that search did not turn up previous reports of this, but perhaps it's swamped.
I had similar with Irfanview last December - On further investigation Windows showed that I had both 32-bit and 64-bit versions installed, but at different versions.
I simply uninstalled the 32-bit version and that solved it, because the 32-bit Irfan view is no longer installed CCleaner doesn't try to update it.
Let's be clear I DID NOT have irfanview 32bit installed and it's NOT the only app I've noticed this on, despite the limited selection. It's just that I could make a screenshot on a fairly fresh W10 install which exhibits the issue.
On some machines I actually installed 32bit by accident, having both irfanviews, other times I gave in and uninstalled 64bit to avoid reoccurence. On my parents office PC I installed 32bit to avoid this issue, which in my experience is totally reproducible, I simply install W10, remove IE and install some "essential" apps, including CCleaner & irfanview.
This has happened to me on clean W10 installs multiple times, it was present on a recent install on a different machine, which unfortunately expired on Sunday, which meant I moved and ran the update advisor on a desktop.
I don't think I've had it happen with 7zip though, which I can install via 64bit MSI, whereas ifranview provides a self extracting .exe and a SHA256 sum to check.
The only advantages relate to immensely large images that most users will not be dealing with (even an 8K BMP photo would only be about 35MB, and even 32-bit IrfanView can open files that are well over a GB), while the 32-bit version is smaller, more compatible, has more features (command-line options, specifically) and has more plugins that work for it.