Why no love for the three piece suit?

Like double breasted jackets, 3 piece looks like costume on most people under 55 y.o.

Rubbish, plenty of younger people look good in 3-piece suits. It's more about attitude than about age.

Yes...

They are actually very popular at the moment with very fitted waiscoats you can wear without the jacket..

Only one of my 15 or so suits is three piece (only one is double breasted as well). I'm usually too warm and never too cold when wearing a suit. My three piece is a HF in a winter-weight gray hound's tooth. I only wear it during the winter months and get a lot of complements when I do.

Twotone

I would disagree. I love 3 piece suits and I am in my 20's. I have at least three 3-piece suits and a variety of odd vests (which I don't wear as often).

It will return when the RTW folk want to ring the changes. In the meantime it is not fashionable for those under 50 and tends to be considered an affectation at the moment.

Formality is declining and modern heated/air con offices also militate against them.

I don't think it's the lack of love that's the problem, it's the lack of occasions for it.

This might be the problem actually, does there really need to be an occassion? In any professional environment that requires a tie, wouldn't a 3-pce suit be...well, suitable?

i'd agree with most everything said here - it's not so much a matter of age, it's a matter of opportunity and use. i know i rarely wear my suits, and so the idea of buying a three-peice (although i love the look) just isn't a good use of my money. i have a tendency to completely disagree with GBR - i think the three-piece is definitely fashionable/in style right now, independent of age.

during the cooler months I'll wear a three piece at least 1 day per week.

+1

Hard to pull off without looking pretentious and out of place

The great thing about a three piece suit is that if you don't wear the waist coat, it's a two piece suit. While some of this seems overly affected, it does present the point that there are several (exactly four) more ways to wear the pieces of a three piece than a two piece.

When I go bespoke, I'm getting a 3 piece. What a fantastic way to increase the versatility of your wears.

I really like this look:
Warning: Spoiler! (Click to show)