The problem when I was at school was that French got taught (generally badly) from years 3,4,6,7,8,9 depending on what school you;d been in. By the time we were in year 10 and choosing GCSE options, I'd done the first year of learning French four times and was embarking on my third go-round of second-year French. Even if the teacher hadn't been terrible (she didn't even notice my skiving off for another term and a half), it would have been pretty boring, even in the top set.
Meanwhile we started German in Y9 (not set by ability) and the teacher managed to make it real simply by translating anything anyone said into German and making us write it down in little books (by page 3 these included useful phrases like '"Oh for god's sake" and "I've lost my contact lens!", and vocab tests were tests on the contents of said books as well as whatever we'd been asked to learn.
What switched most of us onto learning a language and finding it useful was being sent on language exchange trips - we weren't given a choice but were dumped in a familiy's home in France/Germany/Spain, went to school there for a week, and had to cope in a strange household who spoke no English. Day trips as a class to France were pretty pointless for learning French (helped with map reading and transport skills I suppose), and the exchanges where a whole class goes together and hardly speaks any of the destination language don't seem to help much (my school did those in addition as an option). A couple hours getting a monologue from my host mother, with a dictionary on the table, every day for a fortnight - that was crucial.
As pp said, one of the key benefits of learning a language is acquiring empathy when dealing with people in English who don't speak it well - and improving your ability at guessing what they might be trying to say. Understanding bad English is a skill too.