Turgon's Folly

[Maedhros]

Could the Ñoldor of Turgon had been saved?
I have always thought that Turgon messed up big time by not following the advice of Tuor/Ulmo, but can we really blame him?
Why did Turgon became proud and refused the aid of Ulmo?
From the Published Silmarillion : Of Tuor and the Fall of Gondolin

Then Turgon pondered long the counsel of Ulmo, and there came into his mind the words that were spoken to him in Vinyamar: 'Love not too well the work of thy hands and the devices of thy heart; and remember that the true hope of the Noldor lieth in the West, and cometh from the Sea.' But Turgon was become proud, and Gondolin as beautiful as a memory of Elven Tirion, and he trusted still in its secret and impregnable strength, though even a Vala should gainsay it

Now contrast that with the Version of The Book of Lost Tales II: The Fall of Gondolin

Then spake Turgon: "That will I not do, though it be the words of Ulmo and all the Valar. I will not adventure this my people against the terror of the Orcs, nor emperil my city against the fire of Melko."
Then spake Tuor: "Nay, if thou dost not now dare greatly then will the Orcs dwell for ever and possess in the end most of the mountains of the Earth, and cease not to trouble both Elves and Men, even though by other means the Valar contrive hereafter to release the Noldoli; but if thou trust now to the Valar, though terrible the encounter, then shall the Orcs fall, and Melko's power be minished to a little thing."

But look at the alternative proposal offered by Tuor/Ulmo:
From The Book of Lost Tales II: The Fall of Gondolin

but Tuor said, for thus was he bidden by Ulmo who had feared the reluctance of Turgon: "Then am I bidden to say that men of the Gondothlim repair swiftly and secretly down the river Sirion to the sea, and there build them boats and go seek back to Valinor: lo! the paths thereto are forgotten and the highways faded from the world, and the seas and mountains are about it, yet still dwell there the Elves on the hill of Kôr and the Gods sit in Valinor, though their mirth is minished for sorrow and fear of Melko, and they hide their land and weave about it inaccessible magic that no evil come to its shores. Yet still might thy messengers win there and turn their hearts that they rise in wrath and smite Melko, and destroy the Hells of Iron that he has wrought beneath the Mountains of Darkness."
Then said Turgon: "Every year at the lifting of winter have messengers repaired swiftly and by stealth down the river that is called Sirion to the coasts of the Great Sea, and there builded them boats whereto have swans and gulls been harnessed or the strong wings of the wind, and these have sought back beyond the moon and sun to Valinor; but the paths thereto are forgotten and the highways faded from the world, and the seas and mountains are about it, and they that sit within in mirth reck little of the dread of Melko or the sorrow of the world, but hide their land and weave about it inaccessible magic, that no tidings of evil come ever to their ears. Nay, enough of my people have for years untold gone out to the wide waters never to return, but have perished in the deep places or wander now lost in the shadows that have no paths;

Turgon had already done as Ulmo wished but without his aid , the mariners of Turgon couldn’t reach Aman. Can Turgon really be blamed for not leaving Gondolin?
Althought it was because of Ulmo’s advice that Gondolin could first be built.
From the Published Silmarillion : Of the Noldor in Beleriand

It has been told how by the guidance of Ulmo Turgon of Nevrast discovered the hidden vale of Tumladen; and that (as was after known) lay east of the upper waters of Sirion, in a ring of mountains tall and sheer, and no living thing came there save the eagles of Thorondor. But there was a deep way under the mountains delved in the darkness of the world by waters that flowed out to join the streams of Sirion; and this way Turgon found, and so came to the green plain amid the mountains, and saw the island-hill that stood there of hard smooth stone; for the vale had been a great lake in ancient days. Then Turgon knew that he had found the place of his desire, and he resolved to build there a fair city, a memorial of Tirion upon Túna; but he returned to Nevrast, and remained there in peace, though he pondered ever in his thought how he should accomplish his design.

Was it because he was loath to abandon anything he had set his mind to do?
From the Published Silmarillion : Of the Flight of the Noldor

Moreover Fingon and Turgon were bold and fiery of heart, and loath to abandon any task to which they had put their hands until the bitter end, if bitter it must be.

Why is it that he trusted Turgon in the beginning and not in the end?