I like people popping in - but I suspect it is a really marmite thing - and those of us who like poppers-in will never understand those who don’t, and vice versa.
So I think it depends. If you know the person you are popping in on, and know they are fine with it, then great, crack on. But if you know they don’t - or if it is outside of normal popping in hours (at a rough estimate, 10am to 6pm weekdays, maybe afternoons at weekends, but evenings/night times are a no-no except in an emergency - which this was not).
When the dses were little, I had a number of friends and we all happily popped in on each other, but when we moved up to Scotland, I found that people really don’t pop in on each other where I live now - and there is a part of me that misses it. I am a bit of an anxious introvert, so I worry about the risk of rejection, if I ask someone round or try to arrange to go to theirs - so knowing people will pop in suits me - but on the other hand, I have got used to a lot of alone time - ds1 has graduated and lives and works in Kent, ds2 is at home but doing his PGDE, ds3 is away at university, and dh works away a lot so now, whilst I do like seeing friends, I also need my solitude too.
10pm is definitely too late to pop in, though.