I never did receive an answer to this question that I submitted years ago.
About 15 years ago Burr-Brown/TI, together with DesignSoft, offered a very good analog simulation tool, TINA-TI. It was easy to learn, intuitive, versatile and powerful. Burr-Brown/TI offered macromodels and circuit symbols for new analog products that allowed users to easily evaluate and then design those new Burr-Brown/TI products into their circuits. Other semiconductor companies had nothing comparable to offer their customers at that time. It was a big competitive advantage that TI squandered. New product schematic symbols that had been colored yellow with a blue outline (the color scheme of the TI data books at that time) easily distinguished the TI products from any other symbols on a TINA schematic. The op amp symbols were drawn in the conventional manner- the inverting input on the top left and the positive supply connection at the top. Gradually this degenerated to a colorless symbol with inputs and supplies inverted. Substituting another op amp into a circuit often required the circuit layout to be re-drawn.
As time went on, new analog products were introduced without TINA models or even schematic symbols. Some models were introduced as encrypted, preventing a user from knowing what parameters were modeled. It is as if TI lost interest in helping their customers design-in new analog products. As TI acquired NSC, they adopted their "Lab Bench" software, a clumsy, simulation effort that was far inferior to TINA-TI.
Now, for some inexplicable reason TI has pushed TINA-TI even further toward oblivion with the introduction of "P-SPICE for TI" from Cadence. This software is powerful but extremely user-unfriendly, as were all of the commercial Cadence software offerings. Although I have been advised by TI support people that TI has no intention of discontinuing TINA-TI, and they may have been told that, any rational person can see the handwriting on the wall.
That TI has clearly mismanaged their analog marketing support is evident- even the TI website is a chore to navigate. Of course, when TI buys all the analog semiconductor companies this won't matter much but for now, TI is handing over market share to Analog Devices. Why?