It's perfectly normal for people to not answer the door if they're not expecting anyone. I know many people who don't.
Single women on their own in the house, and especially elderly women, as they could be attacked... And also single elderly men are a bit vulnerable too... (Older people are more vulnerable to scams and cons, or someone trying to push their way in.) They are told in no uncertain terms by Neighbourhood Watch, and Carers and Health Visitors, and GPs, and the like, to NOT OPEN THE DOOR if they are not expecting anyone.
Also people who work from home don't answer the door either, because they're bloody working. They wouldn't be able to answer if they were in the office would they?!
Only on Mumsnet is it classed as 'weird' to not answer the door when you are not expecting anyone. In real life, most people don't answer, (when they're not expecting anyone) because of all the reasons mentioned, like scammers at the door, salesmen, people trying to ditch people parcels on you, and energy companies and charities bothering you.
And some of these people are very pushy, and some people are vulnerable and easily lead, and not very assertive, and can easily get pushed around and scammed. Some people sign up to things they don't want to sign up to. I have heard many tales of older people signing up to a dozen charities and giving £100 a month that they can't afford, because they're too nice and a bit gullible, and afraid, and are easily taken in by peoples patter.
Also, there are many tales of people being conned by fake 'tradesmen' offering to fix a roof tile or 2 for £50, and then 'finding' more work that needs doing, and charging them £700 for it, or much more in some cases. And then there's the 'tarmac your drive' scam, and the 'we'll trim your conifers' scam.
Yes yes I KNOW not all older people are not like this, but some are! And it's not just older people who fall for doorstep scams and pressure sales either.
So people can jog on with this 'meh you're a weirdo for not answering the door to anyone and everyone' bullshit! And the oh-so-totes-hilarie' sarcastic comments! 🙄