Many also do but even if not I don't feel I should try to change somebody's mind, may be disrespectful.
That's kinda subjective. If you walk around the site, you'll see plenty of posts where ppl are offered an alternative, whether that's build advice on a budget, talking someone out of a custom loop, offering a better alternative for cheaper with a gpu, buying overly expensive motherboards etc. Ppl may or may not be looking for alternatives, but it's also generally in their best interest that they have an option especially if there's a valid reason for the option. Then it's on them.
Some would argue that not supplying an alternative would be doing the Op a gross disservice as the value of their aim is far less than an alternative, when you are in a position to know of a better alternative solution with much higher value, that would serve them better, for longer, and don't tell them.
For instance, if I'd known Op was planning on purchasing that particular mobo, with maybe possibilities of upgrading the cpu, I'd have tried to find a way to talk him out of that particular board, as it has no public accessibility to 5000 series cpus, even being a B450 chipset. Even a few $ more for a better mobo, and this discussion would have ended multiple posts ago with the posting of 5600G.