The cynicism is that, in addition to suiting startups that haven't got the intellectual capital required to think about a sustainable business strategy as they head into business, it also very much suits YC's approach (see below), which might explain why, as a meme, it's so pervasive!
The YC-like approach could be caricatured as 'shotgun' - throw a load of startups at a wall (boost their launch) and see what sticks (in terms of adoption); but if the rest, which don't show immediate adoption, get neglected by YC-like investors-mentor hybrids too soon, they won't pick up the transferable business skills that would serve them for a lifetime. Putting your hands into a launch-focused incubator is risky, from the startup's perspective.
YC, as first on the scene, has many 'value-added' factors (mainly PR-based) that make this risk worth taking; but copycats don't deliver these (e.g. a great network, great reputation with potential series A investors, media rep, etc). In that light, copycats may actually be more beneficial to the startup scene if they alter their strategy relative to YC to deliver different value-addeds, as Seedcamp does. Probably not worth pooh-pooing them without thinking a bit further, just in case we are letting a damaging meme spread too far without challenge.
The key is to make sure both launch-drive and business training/mentorship are provided in equal amounts - the order in which they come can be debated, and is the nub of the seedcamp vs. YC debate; but let's make sure the complexity of what YC offers comes across - it's not just launch drive and that's not the only important thing in seed stage investment. Long term, that could be very damaging for YC copycats that don't have as clear an idea of what's needed