The same rationale used when docs taper the dose of corticosteroids when they want to take someone off. The mistaken belief by "bros" is that any dose of androgen will completely shut you down as if the HPA was an on/off switch when in fact it is a dimmer. If you go off of corticosteroids cold turkey you get rebound hypocortisolemia which can be very serious because you remve the exogenous surce of hormone and the body's natural supply is severely depressed reuslting in very low cortisol levels in the blood. Tapering allows endogenous production to increase as the exogenous dose is decreased. The same is true for androgens. If you stop cold turkey then you remove the exogenous source while endogenous prouction is at its lowest resulting in a state of very low androgen -- and then everyone wonders where post-cycle gyno comes from. Yes, long esters are self-tapering to a degree but it is not that simple. No you do not need to taper over four weeks but allowing for only the self-taper of an enanthate ester is not enough - especially with higher doses. The rate of recovery (the slope) is slower than that of the self-taper.
Fair point, but I think it really is that simple. As time passes you have less and less active in your system - same thing as tapering, just a shorter time frame. The fact that the rate of recovery is slower then the rate of clearance seems to me to be more or less irrelevant if using a solidly-dosed SERM for PCT. I suggested 1 week because of the high dose, and your rebuttal suggests 4 weeks isn't necessary - so what is the optimal time frame? I hardly think much recovery will be occurring if one tapers from a gram to, say 250 mg over a mere 2 weeks.
Now - I more or less agree with your post if one is using - what's a good phrase here - a "full taper", i.e. tapering off completely. That method was invented to possibly avoid the use of SERMs coming off-cycle, and to allow the HPTA to come back on-line on its own, as you describe. It is, as you know, a long process. My suggestion of a week or so to taper, dropping from a gram to 500 mg, then the normal 2-week wait as the ester clears, is more to allow the OP to stay anabolic and help ease the transition from such a high dose, but it probably isn't absolutely necessary if he is doing a traditional SERM PCT. I will admit it will probably ease the transition, though.
My point is, I believe tapering to be an either/or proposition. Either taper out over the 8-12 weeks and minimize/eliminate the need for a SERM, or don't. I don't see much need for halfway measures when using longer esters, except perhaps a week or so in the case of higher doses, like this. However, this has less to do with HPTA recovery than staying anabolic and helping ease the transition.