My objections to lifestyle or target date investing are very simple: the end result is significantly lower returns, on average.
Let's suppose I have two just options: one is to invest 100% in equities, the other to invest 75% in equities, 25% in cash. Let's also suppose that equities are expected to outperform cash by 4% a year on average. Some years they'll do much better than cash +4%, some substantially worse. The problem is, we don't know what each year will bring which result. We never will.
Starting from that simple premise, I expect a fund invested 100% in equities to deliver 1% a year more on average than a fund invested 75% in equities, 25% in cash.
If I were considering two unit funds, one of which charged 1% a year more than the other, I would always go for the lower-charging fund (assuming they were indistinguishable otherwise). It's the same with investment options. That's why I try to invest as close as possible to 100% of my pension savings in equities, even at my current age (very close to 70).
My proposed smoothing approach to AE aims to achieve the same outcome for people who don't have the same capacity to live with the higher volatility of equities.