I was gonna say, I didn't want to have a go at your original post but I don't see the link between you saying:
"PS1 games as part of the library is a problem" and "PS+ is a problematic selling point".
They're two separate things. One is PS1 games; one is a subscription to access Vita games for 'free'.
And in that respect I agree with you, PS1 + PSP games shouldnt be a selling point for many people (ironically the PSP library is a selling point for me because I never owned that system, so the Vita games I want + PSP games with dual analogue is enough).
But PS+ is different. It's certainly a model that Sony are pushing hard lately and time will tell whether it creates enough incentives for current/future subscribers to invest in a Vita.
But for me personally, PS1 Classics and PSP games wouldn't sell me. Only VIta games would.