When planning a garden, you should plan what you will use the space for now and in the future, when you no longer want a sandbox or such a large vegetable garden. If you plan ahead, you will easily be able to add a perennial bed where the vegetable were, or expand the shrubs into a former play area. Be aware of the amount of sun each area of your garden gets so that you can plan seating areas and plantings appropriately.
A good landscaping plan will incorporate both space and planting. The most pleasing ratio is two-thirds space to one-third planting. Space could include a lawn, patio, deck, driveway, pond or even fences or walls. Planting could also include a feature such as a gazebo or archway. Use several layers in your planting - trees, shrubs and herbaceous perennials or annuals will give dimension to the planting. Incorporate the views outside your yard if you can see anything other than the neighbour's garage, and include a focal point to add interest and draw the eye away from less desirable views, such as the neighbour's garage. In addition to the focal point, let your garden hold secrets - something that a visitor might not notice in a first visit, or that can't immediately be seen from the entrance.
In the end, your garden has to work for you - if you feel most comfortable in a yard that is all lawn or all vegetables, then who cares what Andrew McIndoe thinks? But I think his space to planting ratio solves the question of why a fully-planted "naturalised" yard can be controversial - space allows the eye to rest and sets off the rest of the plants.