As with most things there are good and bad points.
I can see it from where MrsR stands - some people are complete slaves to their damn phones, and have lost all sense of politeness if speaking to someone - it's not "do you mind if I see what this is about" but a switch from speaking to someone in front of them to answering their phone, as if voicemail doesn't exist, and the person nearby is only "secondary" to whomever has called them.
Accessibility is another aspect - if someone is not at work, then turn the flaming thing off if you don't want to get calls asking about things. If you are so vital then you need to discuss who handles things when you are away, and if you are willing to accept calls, fix some timeso there's perhaps a half-hour slot and you can know that you can spend your time with family without being pestered several times a day.
Sure, lots of good reasons for having a phone, but thank goodness everyone is different and it's surely not something to get too het up about - many have excellent reasons for wanting/ using a mobile, and life's too short for arguments over this topic. MrsR is clearly in the minority, but has a right to her opinion and everyone else to theirs, without coming to (verbal) blows about who is "correct" or "unreasonable".
Morloth wrote "Caller ID is one of the best inventions"...
For anyone who wants to know who is calling their landline I can recommend "BT Privacy" (assuming you are still with BT) which gets you listed on the Telephone Preference Service as a "do not call" and provides Caller Display for FREE instead of having to pay 2.50 a month for it.
You have to make a couple of chargeable calls each month (so if you use some other firm like 1899.com for calls, you just don't use the prefix for a couple of calls in a month).
I'm so glad I asked for it when I had my line installed recently, as I've had no end of calls for whoever had the number before me, and most recently, 3 of those American accented pre-recorded calls...
Now if I see WITHHELD or UNKNOWN the answerphone is allowed to kick in, and I can hear if it is a friend or relation...