JT states in his blog Rapture,Tribulation and the End of the World that the term rapture is unhelpful, non-biblical and part of Dispensationalism. Is this correct?

In 1 Thessalonians 4:17 ἁρπάζω (harpazō) means snatch, seize....a rapture to God and glory (Ac 8:39; 2Co 12:2, 4; 1Th 4:17; Rev 12:5 [1]...‘to seize, to snatch away, to take away.’ [2]) ...(to snatch away, carry off ... to seize hastily, snatch up ...to seize, overpower... [3]) ...(to snatch away, to seize... Common Translations - seized; seize; snatch away; snatched away; seizing; carried off; snatch [4]).
The ancient Peshitta version uses the word ܚܛܦ (chataph) which again, means, to seize or take away. [5]
The Latin translation of  ἁρπάζω is raptus (rapere, rapui, rapio) = snatch; seize, carry off. [6, 7]. Raptus is the Latin root of the word rapture and so to claim that it is non-biblical is baseless. Both the word and the idea behind it are firmly grounded in the New Testament.

FF Bruce states: “After the dead in Christ have been raised, we … shall be snatched away together with them” (ἅμα σὺν αὐτοῖς ἁρπαγησόμεθα). The force of the preposition σύν is strengthened by the preceding ἅμα. From the Latin equivalent of ἁρπάζειν (rapere) this incident in the Parousia is sometimes called the “Rapture” (snatching away) of believers. The verb ἁρπάζειν implies violent action, sometimes indeed to the benefit of its object, as when the Roman soldiers snatched Paul from the rioters in the Jerusalem council-chamber (Acts 23:10) or when the male child in the apocalyptic vision was caught up to God to preserve him from the great red dragon (Rev 12:5). It is used in Acts 8:39 for the Spirit’s snatching Philip away after his interview with the Ethiopian chamberlain and (more germanely to the present passage) of Paul’s being caught up to the third heaven or paradise (2 Cor 12:2, 3)." [8]

NET tranlates it: "will be suddenly caught up (Or “snatched up.” The Greek verb ἁρπάζω implies that the action is quick or forceful, so the translation supplied the adverb “suddenly” to make this implicit notion clear."

It would be perfectly acceptable to translate it "...we who are alive and remain will be raptured..."

[1] James Swanson, Dictionary of Biblical Languages with Semantic Domains: Greek (New Testament)
[2] Johannes P. Louw and Eugene Albert Nida, Greek-English Lexicon of the New Testament: Based on Semantic Domains (New York: United Bible Societies, 1996), 220.
[3] H.G. Liddell, A Lexicon: Abridged from Liddell and Scott’s Greek-English Lexicon.
[4] The Lexham Analytical Lexicon to the Septuagint (Bellingham, WA: Logos Bible Software, 2012).
[5] George A. Kiraz, Analytical Lexicon of the Syriac New Testament: Based on the SEDRA 3 Database of George Anton Kiraz
[6] William Whitaker, Dictionary of Latin Forms (Bellingham, WA: Logos Bible Software, 2012).
[7] J. M. Harden, Dictionary of the Vulgate New Testament (London; New York: Society of Promoting Christian Knowledge; The Macmillan Co., 1921)
[8] Bruce, F. F. (2002). Vol. 45: Word Biblical Commentary : 1 and 2 Thessalonians. Word Biblical Commentary (102). Dallas: Word, Incorporated.