I'm of the opinion that Italy and Austria exist in a symbiotic relationship, but its more one-sided than one may initially recognize. Austria is in the precarious position of being stuck in the center of the board and surrounded on all four sides while simultaneously being cut off from sea provinces. For all intents and purposes, Austria can ignore Germany for the first several years, since only a foolish Germany would attack Austria early in the game. Furthermore, even an Austrian player of average skill can hold off Russia with only one or two units, thus negating the Russian influence in the Balkans quite easily. Turkey, though, presents a problem, particularly if the Turkish player is working with Russia, as they often do, especially in 1901 and 1902. But, a skilled Austria can still hold off a juggernaut, albeit with a fair degree of difficulty, and still do very well.
The wild card for Austria, though, is Italy. The Italian can make or break Austria's game, and no other country on the board has that level of influence over another. The Venice/Trieste border is naturally the source of many a 1901 stab, but the stab opportunity is in no way equal. Italy can stab Austria much more easily than the latter can stab the former, putting Austria at the mercy of the Italian almost immediately in 1901. If Italy chooses to work with Austria, he runs the danger of letting Austria grow, and a six or seven center Austria is extremely difficult to dislodge. That same powerful Austria will eventually need Italian centers to solo.
With standard openings from Russia (Southern) and Turkey (Balkan Concentration), a standard Austrian opening (Balkan Gambit, Galician variation), and a standard Italian (Lepanto), Austria and Italy have a far greater likelihood of success. However, should Italy decide to open with an Obriani, I argue that Austria's chance of success becomes virtually zero.
Here's the kicker. With a Balkan Gambit opening, Austria's win/draw rate (according to VaftStats FP stats) is 29.18% (Trieste variant), 35% (Galician variant), and 31.21% (Budapest variant), those three opening constituting the vast majority of Austrian openings. Italy has essentially two options, the Obriani and the Lepanto (for sake of argument, we'll ignore the Alpine Chicken atm). The Obriani sees a win/draw rate of 30%, while the Lepanto has a win/draw of 28.4%. HOWEVER, Italy's chance of soloing DOUBLES with the Obriani versus the Lepanto.
In gunboat, the spreads are similar, but Austria's win/draw probability is decreased by roughly 10% for each variation, accounting for Austria's typically poor performance in gunboat. Conversely, Italy's win/draw for the Obriani and Lepanto INCREASE by the same 10% in gunboat. The moral here is that you do not want to draw Austria in gunboat.
I am always amazed by the Italy who chooses to work with Austria. From the many forum discussions on the topic, there seems to be one reason for this: the fear of the juggernaut. The beginning Italian player is too easily swayed by the threat of the Turkey/Russia alliance steamrolling a weakened Austria and continuing through Italy. With stats taken into consideration, though, it's clear that the skilled Italy player can solo twice as often when they open with an Obriani versus the Lepanto, which too often leads to an Eastern Med stalemate. Of course, we don't have situational statistics to measure the win/draw of an Obriani given a juggernaut, or an Obriani given a Crimean Crusher by Turkey, but that 100% increase in solos speaks measures about the effectiveness of stabbing Austria in 1901. There are simply too many long term variables in the juggernaut, especially on the Russian side, to assume that a Russia/Turkey alliance will steamroll the greedy Italy.
Tl;dr: given the numbers and the power of Italy over Austria, why would any Italian player open with a Lepanto?