There is one benediction Krsna, Visnu or Siva and their devotees can NEVER grant.

The intelligent impersonalist are very knowledgeable, they know Kṛṣṇa is an "eternal Person" and is the Supreme Personality of Godhead and cause of all causes, but do NOT follow Him or have any desire to serve Him.

The impersonalist have great knowledge of the Vedas, especially Bhagavad Gita Chapter 2 that tells them, "the soul is beginningless and endless and will never die."

But they do not accept that and only ask one benediction from Visnu which is to die! To come to an end and cease to exist so they never fall out of the inactive impersonal brahmajyoti.

They know that presently their impersonal beliefs allow them to enter the impersonal brahmajyoti and can remain there for a trillion life times of Lord Brahma but eventually again fall down from their and again and take birth in the material world.

The impersonalist do not want that because while inactive in the impersonal brahmajyoti for a trillion life times of Brahma, which is only a blink of an eye once the soul re-emerges and again takes birth in the material world.

So, a seemingly intelligent impersonalist, who wants nothing do do with the Vaikuntha planets of Visnu/Narayana, or Krsna's central Abode of Goloka-Vrindavana, ask Visnu to grant them (the soul) death and allow them to eternally reside in actively with no sense of self or existence in the impersonal brahmajyoti.

In other words the impersonalists want their identity and personality eternally extinguished. 

But Kṛṣṇa, Visnu or Siva can NEVER grant this attempted spiritual suicidal desire because the eternal nature of the individual jiva-soul in their original position, is being beginningless and endless, and fully "active" serving Krsna or Visnu.

Srila Prabhupāda - "Existence in the impersonal brahman (being inactive and identity extinguished) is also within the category of non-Krsna consciousness and is also only a temporary condition (because the nature of the soul is to be always active in Krsna's pastimes.) Those who are in the brahman effulgence are also in a fallen condition, so there is no question of falling down from a fallen condition. When fall takes place, it means falling down from the non-fallen condition (Goloka-Vrindavana and Vaikuntha). The non-fallen condition is Krsna consciousness." (Letter to Revatinandana dasa, LA 13 June, 1970 and 1971 London)

Srila Prabhupada – "There are no new souls, new and old are due to this material body, but the jiva-soul is never born and never dies, so if there is no birth, how can there be new souls?" (Letter to Jagadisa dasa, 9 July 1970)

Srila Prabhupada - "God is also an individual person eternally as you are individual person eternally, I am individual person, but the difference between God and you and me is this, that you know your business, I know my business, but God knows everyone's business. That is the difference." (Lecture Melb, Australia April 3, 1972)

Bhagavad Gita As It Is - "Never was there a time when I did not exist, nor you, nor all these kings; nor in the future shall any of us cease to be." (BG, Ch 2 Text 12)

Bhagavad Gita As It Is - "As the embodied soul continuously passes, in this body, from boyhood to youth to old age, the soul similarly passes into another body at death. A sober person is not bewildered by such a change." (BG, Ch 2 text 13)

Bhagavad Gita As It Is - "O son of Kuntī, the nonpermanent appearance of happiness and distress, and their disappearance in due course, are like the appearance and disappearance of winter and summer seasons. They arise from sense perception, O scion of Bharata, and one must learn to tolerate them without being disturbed."(BG, Ch 2 text 14)

Bhagavad Gita As It Is - "O best among men [Arjuna], the person who is not disturbed by happiness and distress and is steady in both is certainly eligible for liberation." (BG, Ch 2 text 15)

Bhagavad Gita As It Is - "Those who are seers of the truth have concluded that of the nonexistent [the material body] there is no endurance and of the eternal [the soul] there is no change. This they have concluded by studying the nature of both." (BG, Ch 2 text 16)

Bhagavad Gita As It Is - "That which pervades the entire body you should know to be indestructible. No one is able to destroy that imperishable soul." (BG, Ch 2 text 17)

Bhagavad Gita As It Is - “The material body of the indestructible, immeasurable and eternal living entity is sure to come to an end; therefore, fight, O descendant of Bharata." (BG, Ch 2 text 18)

Bhagavad Gita As It Is - "Neither he who thinks the living entity the slayer nor he who thinks it slain is in knowledge, for the self slays not nor is slain." (BG, Ch 2 text 19)

Bhagavad Gita As It Is - "For the soul there is neither birth nor death at any time. He has not come into being, does not come into being, and will not come into being. He is unborn, eternal, ever-existing and primeval. He is not slain when the body is slain." (BG, Ch 2 text 20 "corrected" 1983 edition)

Bhagavad Gita As It Is - "O Pārtha, how can a person who knows that the soul is indestructible, eternal, unborn and immutable kill anyone or cause anyone to kill?" (BG, Ch 2 text 21)

Bhagavad Gita As It Is - "As a person puts on new garments, giving up old ones, the soul similarly accepts new material bodies, giving up the old and useless ones." (BG, Ch 2 text 22)***