Different concerns apply to children of different ages or temperaments, and to different situations. My seven-year-old daughter is actually better than most at entertaining herself with books or puzzles etc. She also has a mother who stays home. Thus, when I work from home, she's quite capable of leaving me alone and knows to do so. During the evening or weekends, though, it's perfectly reasonable for her to request my attention pretty often. My wife deserves her breaks too, and there are no siblings. Someone who would completely shut out a seven-year-old during those times, under those circumstances, is IMO too selfish to be a decent parent - or for that matter husband, colleague, ...
If your child is a different age, or has siblings, or is even more exceptional in terms of self-entertainment, or if you're content to plop your kids in front of a TV/computer for hours on end, or if you have other family/friends willing to take your kids often, then maybe you're able to achieve longer periods of concentration. Good for you. Please don't assume, though, that your circumstances and thus your choices are applicable to others. Among the hundreds of other parents I've talked to, this issue of limited and fragmented free time is a major challenge for every single one.
If your child is a different age, or has siblings, or is even more exceptional in terms of self-entertainment, or if you're content to plop your kids in front of a TV/computer for hours on end, or if you have other family/friends willing to take your kids often, then maybe you're able to achieve longer periods of concentration. Good for you. Please don't assume, though, that your circumstances and thus your choices are applicable to others. Among the hundreds of other parents I've talked to, this issue of limited and fragmented free time is a major challenge for every single one.