I've been thinking about this and realise I hardly ever recommend books or indeed most stuff I really, really love to people unless they actually ask me about it first? I think it's a combination of factors that are mostly selfish... Like I'd feel a little insulted if they didn't agree with my taste perhaps? Or if they did that they might like it too
A kind of 'chocolate tastes better when you're on your own' - very, very silly and greedy person me.
I think with Terry's book it does perhaps centre on the humour/satire aspect and with his associations with SF&F and how it doesn't always 'sit' well with the purists? In recent interviews he's compared Discworld with LotR (and with Minas Tirith in fact as the great metropolis of Endor) '500 years on' because, I think, that's the only nearest populist genre in terms of timeframes and indigenous species and also the 'not doing magic' that can describe his writing to people who aren't reading him
Except Discworld is nothing like LotR in the fundamentals and I know for a fact that most avid LotR fans look down on Discworld because it's funny and because sends Terry sends up everything that's serious. There's very little powerplay that's 'noble' or 'evil' or even 'right' in Terry's writing in comparison with the pretentiously earnest concerns of Star Trek or, much as I love him, Tolkien (I'd rather have my eyes poked out with sharp sticks than contemplate reading the Silmarillion cover to cover ever again). My housemate appreciates Discworld, especially Witches Abroad
(he was a travel agent) but he's not a book reader and he's never actually read it all the way through or any other Discworld book either. Like me, my sister adores Tolkien, Asimov, Jane Austen and Monty Python but she can't stand Discworld - she's the only person I've ever really raved about it too and she just doesn't like them at all.
I think it's almost certainly the satire and how good you are at interpreting it. Housemate's not terribly intuitive/sensitive but he loves stuff like Red Dwarf
and (showing my age now) Hoards of the Things
an obscure LotR parody on BBC Radio 4 way back in the early '80's and as we're on parodies Bored of the Rings
too. Maybe it's that? People don't like having 'their' type of books 'ridiculed' or disrespected - which is certainly not
what Terry does at all, but they just don't get that he's actually holding up deeper traits and ideas for examination in an analytically ironic fashion on the platform of fantasy.
So I don't recommend him much except in general terms and with the big disclaimer - he's not everyone's cup of tea...