The diminshing of the characters

[Lalaith]

I don't think Inderjit meant "diminish" in a perjorative sense. But the feel of the Silmirillion is altogether "higher" and perhaps more noble. It is in the Aristotlean tradition of tragedy - something which provokes pity and fear.
LOTR is as others have said accessible - not just in its style but also in its subject matter. You might wish you were Aragorn and co on a dangerous, exciting adventure, but no-one in their right mind would wish to be Hurin or Turin, no matter how much you admire them.
On a slightly different note, this subject has reminded me how excited I was when I first got the Silmarillion and the solutions to so many previously unanswered questions. I got into Tolkien as a child, before the Sil had been published, and very frustrating it was too. I remember writing to the publishers and hassling them, asking when it was coming out. I still have my treasured first edition copy..