I can understand the desire for isolation in the mountains, but unless you pony up and purchase the peak it belongs no more to you than anyone else. In 1910 the U.S. population stood at 92 million. By 1960 there were 180 million and now we have 305 million people in this country. Sadly, the mountain and peak population has not kept pace. So to expect, or even demand, solitude and no humanly trace whenever you decide to use the mountains as your personal retreat is pretty delusional, if not selfish. On the other hand, if you have access to a time machine, set it for 1776 when only 2.5 million lived in the colonies and the man to mountain ratio was much more favorable to the isolationist. And the mountains.
I personally don't like ostentatious displays like flags, crosses and anything else that 1/305,000,000th of the population has decided everyone else will absolutely love!
I've no compunction about tearing something like that down, though I rarely do. A simple, small pile of rocks -- enough to protect a register and/or designate the high point on a broad peak -- I think is appropriate.
The metal plaque on LeConte is, in spite of my sympathy for the family, way over the line despite Secor's acceptance of it. He writes, "A plaque in memory of Kyle W. Ebeling has been placed at the base of the north face of Mount LeConte. This landmark serves as the starting point for four of the routes described here..."
Finally, registers truly are time capsules. A few years ago while on Rattlesnake Peak in the local San Gabriel Mountains I signed a register that went back over 25 years. Earlier in that register was written, "Jean Isola June 25, 1976 #215." Jean had also written one word, "Hot." It was to be the last word she would ever write, because she perished from heat exhaustion on descent, having attempted this peak in 100+F temps. Hiking the same hike, sitting on the same peak and holding the same book... I made a real connection to her and it enriched my experience.
My fondest moments on peaks, however, are in the Sierra whenever I find my dear friend Patty Rambert's signature. She's alive and with me there. I can't tell you how satisfying that is.