(a) Yes.  This is the best explanation of why the law does not make a person legally liable for any kind of careless (negligent) act which causes harm to another person. To apply such a broad principle would open up so many potential claims that the courts would not be able to deal with them all. Being exposed to the danger of being sued would discourage people from doing many of the things that we generally think are justifiable and useful, even if they involve a risk of causing a degree of harm to someone somewhere.

 Lord Atkin made the point in Donoghue v Stevenson [1932] AC 562 when he said:

 "But acts or omissions which any moral code would censure cannot in a practical world be treated so as to give a right to every person injured by them to demand relief. In this way rules of law arise which limit the range of complainants and the extent of their remedy."

Current legal developments certainly don't indicate that the limits will disappear. On the contrary, experience has shown how justified the practical concerns are, and the current trend is, to preserve some limits on liability for Negligence rather than do away with them altogether.