Stupid companies have titles and titles are associated with more pay and and more respect. It so happens that people who went to a 2 year technical school would call themselves "programmers" and then those who went to a 4 year college and worked for 5 years don't want to be called by the same label, so they have to invent something sounds harder to get, something more prestigious, so now they are "software engineers". Just like chemical engineers, it implies a certain difficulty of attaining this title, and it is used to differentiate the ranks. But it doesn't stop there, then there is more stupidity there is "Programmer II" vs "Programmer VI" vs "System Architect".