Looks comes into it. Modern bikes are discordent and garish, mountain bikes either look like a motocross bike that's had it's engine stolen or they look broken backed some how.
The curse of the disc brake has a lot to answer for, they look puny and badly proportioned. To get the proportions right they'd need to be at least half the diameter of the wheel but then they'd throw you over the handlebars... Their main crime though is that the rim no longer needs to be a swept surface so they've become another advertising hoarding.
A good indicator of the visual state of the bicycle industry is the road bike. It's hard to get a road bike to look ugly but a combination of carbon spokes, deep rims, aheadstems with too-chunky lugs and and a seat pillar with height indicators [Are you going to use it as a ruler?] usually does the trick. Even stalwarts like Villier Triestina's look minging now.
Maybe I shouldn't put so much judgement on appearences but a lot of people don't have a shed, so they'll need to keep their bike in the hallway. So even when they aren't riding it they'd have to look at it everyday. I also find it hard to differentiate 'proper' modern bikes from the latest B.S.O's these days. Once it was easy, with a simpler shape the B.M.X cranks, chrome rims and flat sheet calipers stood out at 20 yards, now until you are on top of them all bikes look busy and you can't see what they're hiding.
Cost; if I wanted to replace my beloved Stumpy with the equivalent modern one I'd need to shell out £1.549 according to What Mountain Bike [And Mikee's right; stern faces rule!]. I've had a quick search on Autotrader and for the same price I could get a mint and pretty rare 2nd hand Laverda Ghost 650cc or a discounted new Honda CBR125 and still have money left over for new helmet, riding gear, insurance and a house full of petrol.
Maybe modern bikes are more capable but that's meaningless because I still wouldn't have the skills to get anywhere near their best out of them. Actually no, I did a mountain bike skills course at Whinlatter this year and I could outbrake lads on full disc bikes; on my 20 year old resin canti'd Marin.
Final thought. This January we went to the bike show at Excel in London, usually any combination of shiny stuff and outdoor activities perks my interest but this just left me cold. Nothing inspired me and I wouldn't have parted with money on any of the bikes there.
