Only to those with no ambition in my point of view- we constantly see things that are out of our normal skills or knowlege, but if we had no ambition we would never attempt to design them, if we'd even thought about it, let alone make them.
Defeatists will always be defeated, the ambitious will only ever succeed- even if the project is never finished it will always have taught them something, and knowlege leads to future successes.
When I was 15 I went on the 45' Windermere steam launch Shamrock. When I got home I designed an 8' model from memory, all solid oak/mahogany/cedar construction, live steam plant with self designed loco' boiler and all the details I could remember. I started building, steaming .25" square oak for the frames, cutting planks, making a stem and apron, making a raked cabin and engine cover etc. I never finished it, I doubt I will, but the lessons I learnt have stood me in good stead for expanding my hobby, and even leading to employment.
As a 15 year old if I'd said 'wow, I could never build something like that' where would I be? And no I wasn't born with a silver spoon in my mouth, I was using a paper-round to pay for the wood and a bandsaw- of which still has regular use in my workshop.
As a result I feel very strongly that we should always build the best we can and be rightly proud of such- not to put off would-be modellers, but to inspire them.
Greg