This isn't too surprising at all. Democrats would've been better served had they re-nominated Bill White. He only lost by 12 in one of the most Republican years imaginable, and against an incumbent.
Still, I could see Dan Patrick saying some things that would make the Lt. Gov. race closer.
Had the Wendy wave never swept in, he just might have. He was never interested in Senate, but polling did have him leading Perry in the Gov race. He had a ton of Indie support and could actually convince Texans that Perry was too dysfunctional to run the state and while Abbott is certainly worse than Perry, Davis is just too polarizing to win.
And hopefully, since this is PPP, news stations give up on this being a "total tossup" already. Davis would be lucky to avoid a double digit loss and Van de Putte at best would lose to Patrick by about 8.
Most of this post has me rarely agreeing with your assessment. However, that last sentence of the first paragraph is wrong. Abbott is a far better candidate than Perry ever was. He's united Republicans quietly behind his candidacy (Perry's last race was a contentious primary, and he probably would've had another), and his candidacy doesn't allow for a referendum on Perry's policies.