For some reason, and while admiring his compositional skill in pretty much all departments, Mendelssohn's music fails to grab me such as so much music can and does. This is, with me, generally true with composers from that era (such as Schumann). For me, it's all very well written, attractive, entertaining, pleasant, ekcetera, but it falls short of a certain zest music from other periods has. A certain lack of drama, humour, emotion? Too placid, civilised, well-mannered? I don't know...
Of course, we all have our composers we like more than others. But for me, interest stalls a bit after ± Beethoven and only picks up again when the likes of Bruckner, Wagner, Mahler and the like start shaking things up.
This was particularly noticable when, a few years ago, I attended a series of concerts in which the Belgian Quatuor Danel presented 6 string quartets by Mieszyslav Weinberg, two in each concert and seperated by a Mendelssohn quartet. To me, the Mendelssohn quartets didn't "work" anything like the Weinbergs. Not even the op. 80 one, despite the fact that I find that one the best of the ones MB wrote.
I do have a fondness for MB's early orchestral works, though (the string symphonies, esp. 7-12, and the early concerti. But these are of course founded on the likes of Bach, Haydn, Mozart and early Beethoven).
To make things even more puzzling perhaps, I'm not so very much moved by Mozart either, much as I love a number of his works. Perhaps there's something of the same reason behind that...
gep