Yeah I agree, but not because they're toy-ish but because they deviate from the standards that users expect. The example you gave is bad because of the background, wasted space, layout, tabs and buttons not looking like what users expect and the general clutter of it. Good design is not achieved when there is nothing left to add, but when there is nothing left to remove.

To paraphrase Donald Norman, as little knowledge of how to use the object as possible should be held in the head, it should exist in the "world" (in this case the UI). A good UI design is split into categories to reduce clutter thus preventing the need to memorize actions and locations (knowledge in the head), each item should use metaphor (icons to represent real-world items, pushables "sticking out", draggables that look like they can be grabbed) and logical mappings (sorting a list is done via its column header, use of colours to signify categories) to draw on knowledge that people already have and make things obvious. When there's no other option, use standards; *most* people know how to operate a drop-down list or combo-box because they've used loads of them before.

The problem with programmers or engineers being designers is that we believe we are normal users when we're not! I may have read Norman's design book and Spolsky's UI book, but I still suck at making user-friendly designs because as soon as I start hacking I my innocence is soiled by the technical knowledge I acquire. This is the greatest challenge of UI design and why most apps look like crap.