I think it's been the case for many years that far more children take up the guitar than the violin....maybe not through formal school lessons.

There were a few kids at my school, nearly 50 years ago, who were learning guitar through school. I don't recognise the "not a real instrument" comments at all...guitar wasn't looked down on, it was just that more kids studied violin, cornet, flute etc at school than guitar. However, informally, probably 3-4 times as many kids in my year had a guitar at home as those who learned violin, and either taught themselves to play or got slightly older friends to give pointers.

Almost all the violinists gave up in their late teens or early 20s. Most of those I'm still in touch with who had a guitar still have one and at least occasionally get it out.