The entire gaming market is going through a shift right now and it's easy to say that exclusives don't make that much of a difference, but I look at it differently. Every platform that you own...whether it be a PS Vita, XBOX ONE or PS4...it's all about a combination of everything. The reason Sony always gets a strong lead out of the gate with the exception of last generation is because of their history. When Sony launches a console, history shows that they are committed to developing a great lineup exclusives over time...just take a look at every sony console compared to the competition it was going up against...Sony wins in overall 1st party titles that range from decent to classics. All the way back to Crash Bandicoot at the start to Uncharted now.
IMO you need a solid library and exclusives are the cherry on the top that could be a deciding factor for a few million people. GENERALLY, a combination of strong 3rd party support + strong 1st party support is what it takes to win a generation. Microsoft has lost 2 out of it's 3 generations because they never built a strong library of internal exclusive properties outside of HALO and Gears of War. Forza is a great racing franchise (the best for about 10 years), but it's a racing franchise...any team can get together and make a solid racing game. Exclusives build an audience slowly over many generations such as Sony does generation after generation...just as Nintendo has done since the 80's.
Exclusives CLEARLY matter and bringing up Tomb Raider as some sort of proof as to why it doesn't matter is a narrow way of looking at it. The Tomb Raider franchise was never an exclusive franchise and is something that has been played on multiple platforms since it's inception in 1996. You have to look at exclusives over an extended period of time to get a clearer picture as to what is going on.
He is 100% right about the PS Vita though