I read through this therad, I feel Nachinar has given a biased narration of Smathaism, which is evident from the fact he gives short shrift to the central idea of Smarthaism, namely, fidelity to Dharmashashthras. He does concede Smarthas "wanted to emphasize the role of the Smiritis/Dharmasasthras", but chides immediately, "this criticism does not take into account the seminal role played by the Smartas in strengthening Hinduism".
The seminal role they played is to inject their poisonous Varna ideology into Hinduism and make it the central aspect of it. Their contribution to Hinduism is the most visible blot on Hinduism, namely Varna system. SVs led by Ramanuja fought against this, but failed in more than one way. They not only failed to make any dent, but the SV tradition itself degenerated into something indistinguishable from Smarthaism with respect to Varna.
Smartha religion is none other than Brahminism. They did not strengthen Hinduism, they ruined it with the Varnashrama dharma doctrine. So what if they are eclectic with respect to the gods they worshiped, they were the very definition of narrow minded hierarchical exclusivity with respect to our fellow humans. Their brand of the eclectic turns the meaning of eclectic on its head.
Given the arc of history bends towards justice, for Hinduism to survive as a religion, smartaism aka Brahmanism must cease to exist.
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p.s.
I also feel suraju got it wrong, he was confusing Sri Vaishnavam with Vaishnavam in general. The SVs are the most exclusive, for them only Sriman Narayana is supreme godhead, all other gods are demigods to be ignored. Gaudia Vaishnavas celebrate Shiva Rathri, SV's will never do that. Madhwas have no problem worshiping Vinayaka, I think, somebody correct me if I am wrong, SVs will never do that.