--- If you are engaged in sodomy in your house, the government can't come in and do anything about it, because the private bedroom is sacred, and we want to keep the state out (or so the logic goes). But, if you are just watching TV in the sacred marital bedroom, the government can kick you out and demolish your house (marital bedroom and all).
--- The government can't quarter soliders in your house during peace time. But, if they are adamant, they can take your house away and put anyone there who they want.
The difficulty of this decision is not its deferential view of public use. The traditional conservative view of state legislatures demands deference. After all, those who advocate for a more robust, judicial policing of the public use clause seem to call on judges to step in and rule that a use deemed public by a legislature (or at least claimed to be public by the time the legislature's graft is haled into court), is really not in the public interest at all.
A hallmark of the recent conservative/liberal divide, though, has been over deference to state legislatures on grounds not easily provable under standard social and natural sciences. For example: Everyone is comfortable deferring to the legislature where the entire environmental community is on board. Everyone is happy rubber stamping economic legislation based on Nobel prize winning economics.
But we don't need legislatures for that type of work. If all we wanted out of life was deference to aristocratic experts, we wouldn't need to gather democratically elected representatives in state houses across the country.
Democratic governance is a tricky business. Millenia ago, Plato pointed to the foolishness of letting expert decisions be made by non experts. But we, at least in the part of the country which still values elected democracy (which includes Lord Coke when he returns home from New York to Ohio), are willing to give up expert leadership in favor of leadership by majority will.
There are too many values embodied in this principle to fully explore here. But one is particularly relevant for the Kelo decision. One set of experts may say that demolishing the Kelos' home in favor of private industrial development is bad for the economy. Others may see it as beneficial for the local economy. Others may see it as harmful for the environment, while still others may see it as improving the psyche of the neighborhood by showing corporate interest in the area. The point is that there is no single set of expert opinions which can police a "public use" requirement, since the public interest cannot be defined by any finite set of knowledge now at are disposal. Thus, there are no standards available to courts to evaluate the public nature of a taking. But rather, we have no choice but to assume that the public is interested in any project which a majority of legislators (whether by hook, by crook, or by legitimate interest in the public good) agree is in the public interest. In the chaos of a legislative vote, all of the various interests in land described above (and many more) can be voiced, shaken out, and driven to compromise. This process of compromise is the only method available to government now to balance competing conceptions of "public use."
Inconsistency arises more in other jurisprudential areas than in this one. After all, the same reasons which demand we trust legislative assessments of "public use" for takings demand we trust legislative assessments of "public interest" in criminal law, housing law, family law, etc. All of those cases present myriads of experts and theories demanding a place at the policy table. Only by trusting legislatures and removing the temptation to interfere judicially can any reasonable balancing of competing interests and ideals occur.
But the Supreme Court has not truly allowed this deference in other areas. Any interest which cannot be neatly cabined into an ivy league academic department is classified as "moral," a term used by recent federal jurisdprudence to refer to justification for an interest not based in the generally accepted social and natural sciences. But while it is tempting to enforce some rigor on legislative ideologies, the principled reasons we have majoritarian rule in the first place is violated if we demand such explanations.
So, while I understand why the court refused to honor the liberty interest of privacy in the property context in the face of contrary legislative intent, I can only hope that this same logic will be extended to other areas of judicial supervision of majoritarian politics.