I HATE it when people pop in unannounced and I don't give a shit if that makes me a grumpy old fuck. Similarly I NEVER turn up uninvited to anyone's house either. It's rude and arrogant and you are assuming people have fuck-all else to do, apart from entertaining YOU.
And it pisses me off when people say 'what happened to the days when you could just rock up to someone's house and be made welcome yada yada!!!'
Was there EVER a time when everyone was OK with people just turning up unannounced?! Maybe some people who didn't work (home-makers) and whose kids had left home, and who had no hobbies and few friends, but most people I have ever known have always had quite a busy life, and don't have time to entertain and cow-tow to people who just roll up at their home uninvited!
And back in the 1970's and 1980's, even my non-working older relatives who were were born in the 1920's and 1930's and whose kids were grown, didn't care for people just 'popping in' and staying for hours, eating them out of house and home, expecting to be waited on hand and foot, and stopping them relaxing in their own home.
As I said, when has this ever been a universally loved thing? Having people popping in without warning, and staying for hours? OR days!!!
I remember a long time ago, my friend had a penpal from from overseas (I won't say where!) and she was only writing to her for about 3 months, and on around her 4th letter, this woman said 'be ready for a nice surprise soon......' My friend thought she was going to send her a gift.
You can probably guess what is coming next........
The woman rocked up at her house, with a huge suitcase! Totally uninvited and totally unexpected.
Problem was, when she came, (at midday on a Saturday,) my friend was out all day on a big city visit approx 40 miles from home. And there were no mobile phones then or texting or instant messaging - it was mid 1990's... Then when she was done with her city trip, she came back to the little town she lives and went to the cinema til 11pm. (Completely oblivious to the fact that this penpal had been waiting for her since midday. )
She had been waiting at her flat door, she had knocked on the doors of a dozen neighbours, (to see if they knew what time my friend would be back, where she was, and if they had a key so she could let herself in!) 
And she had tried to locate my friend's parents by looking in a phone book that she found in a phone box. (She knew they lived only half a mile away, as my friend had mentioned this in one of her letters,) They were ex-directory so weren't in there. PHEW!!!
She had gone into town for a meal at 3pm and come back, then tootled off again at 7pm then come back. Awkward. My friend knew this because her neighbours (who the woman had been badgering half the day demanding to know where my friend was,) told her.
Seems she left at 10.30pm after asking 5 or 6 sets of neighbours if she could stay there, and got a B & B with a view to 'popping back' to my friend's at dawn the next day.
My friend was horrified as she didn't know this person, they had only been 'penpals' for 3 months, and had exchanged only 3 or 4 letters at the most, and she was expecting her to let her stay at her home. So she just didn't answer the door when the bell rang at 7am. (She couldn't tell she was in as it was an upstairs flat in a 3 storey block, (on the top floor,) and you couldn't see into it.
The bloody woman just waited til TEN a.m. then popped off. My friend played hide and seek for several days til the penpal actually gave up!
She got a letter from her later in the week saying she had called to see her, but she couldn't manage to catch her in PMSL! So could she ring her on this number (B & B's number) and they can arrange to meet...
My friend never wrote back, and never saw the woman again. Guess she moved onto another sucker penpal!
So yeah @MakingABoobOfIt YANBU!
To the people saying 'why is that even FAMILY cannot visit unannounced?' It's because people have busy lives, and aren't sitting there waiting for you to come, so they can entertain you, and wait on you hand and foot! And they don't have to answer to you, or explain themselves. NO, not even if you are their PARENTS! 