There are some good reasons for the 14th. How would you feel, for example, if you lived in Minnesota and someday it elected a Moslem governor and Moslem-majority legislature, and they enacted a law making it a felony to blaspheme Mohammed or the Koran?
It’s one thing to have a laboratory, but if some state or locality were to whip up the legislative equivalent of Covid-19, that should be impermissible. Certain basic rights - those in the BOR, apply to ALL Americans, and simply cannot be violated. In fact, that is exactly what is at issue here, and what was at issue in McDonald. We have states that would - any basically have - enacted laws that banned entire classes of arms (not just firearms, but things like brass knuckles and switchblade knives) and effectively banned the right to carry outside of one’s home. Are you in favor of such “laboratories” that are the wet dream of the statists and Leftists (but I repeat myself)?
Better to confine it than to allow infection of the entire country! That's part of the point in Federalism subject to Natural Law competition among relatively independent jurisdictions with well-defined limits to common authority.
To your tacit point, Islam is a special case because it is a completely alien form of government antithetical to Constitutionally limited powers, having no respect for the free exercise of any other religion. Hence, its adherents are not parties to the social contract that is the Constitution and therefore, to my mind, not deserving of its protections. But that is a separate discussion.
Remember too that an antecedent to the 14th Amendment was the the 14th Article of the original BOR which was rejected by the States. It took the Civil War followed by a 14th Amendment enacted via secret construction, hasty passage, and coerced ratification to force that centralization of powers upon the several States. It's not a happy legacy.
Certain basic rights - those in the BOR, apply to ALL Americans, and simply cannot be violated.
This is simply inaccurate historically and legally as the BOR has NOT been fully incorporated. Consider regulatory takings as an example, or how long it took for the 2A to come under Federal protections. Instead, that selective incorporation process has proceeded stepwise. That is the essential problem of the 14th Amendment as opposed to the 10th. What Constitutes a protection of rights and liberty to one person is a violation to another. That's what happens with competing claims for rights are enforced by a central government.
Are you in favor of such “laboratories” that are the wet dream of the statists and Leftists (but I repeat myself)?
Inasmuch as I consider the consequences of leftist authority an abomination, I'm obviously not a fan. But in a way, I do want things that way, in that it would give Natural Law a chance to exert its 'enforcement' instead of all this legalism and bureaucracy with its many structural pitfalls. With States having full latitude, those jurisdictions enacting such leftist abominations would fall into chaos. People would leave. The rest of the country would enact stronger protections for rights. Eventually those awful States would collapse. That's why I am fine with the (to my mind) evil manner in which California has instituted sexual depravity. I want the rest of the country to understand why that sort of license is such a bad thing instead of accepting the slow poison of half measures coerced by the spectre of witholding Federal funding.
I gave you the example of Kelo, so consider Dobbs as an example of what I mean. Some States will institute outrageous protections for abortion and abominal variations on artificial reproduction as a result. While others will try to enforce vaguely defined protections for life that will then enforce measures that end up being cruel and invasive. The States will experiment with measures that reflect rapidly changing technologies and we will get to watch the consequences develop over sufficient time to see multigenerational consequences, which is why allowing that degree of distinction is important. Enforced uniformity has its own deleterious consequences.
The 14th has been a conduit for an enormous amount of mischief, particularly as regards environmental and regulatory law that goes unnoticed by the public because it IS unform. As a result with (unconstitutional) Federal lands we have enforced uniformity in forest non-management which has precluded large scale examples of superior management, not to mention having served corporate interests to no end exploiting their own lands to greater profit while precluding competition, thus raiding the pocketbooks of every American. There would be no way for activists to claim the outrageous fires we have seen as consequences of "climate change," were whole States able to make their own management decisions.
In other words, "enforced uniformity" can be uniformly bad. So while allowing Natural Law to exerts its punishments does take time and certainly harms its victims, perhaps Federalism allows its "instructions" to take effect without need for expensive and corrupt bureaucracy and courts to be the only functioning means. Look at the cost of that overhead in California.