A noted exception to the general observation resulting from the existing historical records, that Thetis was not venerated as a goddess by cult, was in conservative Laconia , where Pausanias was informed that there had been priestesses of Thetis in archaic times, when a cult that was centered on a wooden cult image of Thetis (a xoanon ), which preceded the building of the oldest temple; by the intervention of a highly placed woman, her cult had been re-founded with a temple; and in the second century AD she still was being worshipped with utmost reverence. The Lacedaemonians were at war with the Messenians, who had revolted, and their king Anaxander, having invaded Messenia, took as prisoners certain women, and among them Cleo, priestess of Thetis. The wife of Anaxander asked for this Cleo from her husband, and discovering that she had the wooden image of Thetis, she set up the woman Cleo in a temple for the goddess. This Leandris did because of a vision in a dream, but the wooden image of Thetis is guarded in secret. 
To see the views of others you have to be more than willing to investigate. You actually have to "do the work". In doing so, you will find the evidence used to support the findings of those outside of the mainstream. It's the work I had to do myself, because my education didn't present me with that content; nor did any research assignments lead me into a 'phase of discovery'. That phase was launched in 1988, while I was working on my Superintendency Certification. It was a painful exploration but one that helped me overcome my educational programming. I am still exploring and find this site to be invigorating.
Lycophron, Alexandra 856 ff (trans. Mair) (Greek poet C3rd .) :
"The recesses of Lakinion (Lacinium) [in Italy] wherein a heifer [Thetis] shall fashion an orchard for the goddess Hoplosmia [Hera], furnished with trees. And it shall be for all time an ordinance for women of the land to mourn the nine-cubit hero [Akhilleus (Achilles)], third in descent from Aiakos (Aeacus) [grandfather of Akhilleus] and Doris [Thetis' mother], the hurricane of battle strife, and not to deck their radiant limbs with gold, nor array them in fine-spun robes stained with purple--because a goddess [Thetis] to a goddess [Hera] presents that great spur of land [Lakinion] to be her dwelling-place."