This question was raised specifically with regard to first-term Diet members, who are typically the most vulnerable. As usual, I gave a long-winded answer, which I am going to reproduce in more coherent form.
The LDP Diet members who managed to pull through anyway in the 2009 LDP debacle that brought the DPJ into power do not fear a snap election. There is very little risk as far as their personal prospects are concerned. They are quite willing to let the prime minister choose what he deems to be the optimal timing as far as the interests of the LDP is concerned.
The LDP members who lost in 2009 but made it back in the 2012 landslide victory that brought the LDP-Komeito coalition back to power are in a much more ambiguous position. For them, a snap election means betting the certainty of two more years against the uncertainty of four more years. The hasty rush towards a snap election even before the decision regarding the timing of the next consumption tax hike is made indicates that the typical LDP Diet member thinks that the uncertainty is low enough to make a snap election worth looking forward to. My guess is that the Diet members who made it back generally fall into this category.
Rookie Diet members who did not inherit family heirloom seats—their number is unusually high this time—are typically the most vulnerable. They would very much prefer to spend the next two years building and consolidating their support base and collecting funds to repay the debt that they incurred in launching their (national) political careers, rather than run the risk of losing everything—a significant possibility even in the case of a modest 20-seat drop-off for the LDP. Unfortunately, single-term members are relatively powerless as far as decision-making in the LDP is concerned. Their personal interests will carry little weight, leaving them to sink or swim.