Bacause it's absolutely not flawed, it's the same thing: it shows that success relies on the investements made by the manufacturing company.
For PS3 the big problem was to accept huge losses (investements) to price the system decently. If they they had not done that by keeping the price at 600$ for two years, PS3 would be dead.
For Vita, price in under control compared to PS3 and price cutting is easier, honestly I don't think they'll have a hard time to price it at 199$, but software support is more difficult compared to PS3 because it's an isolated platform without other similar platforms to share the development costs' burden, so they need to secure key third party games by investing in that field. They need to go to big publishers/developers and say "I want this game on my platform, I will pay most of its development costs for you, profits will be shared among us".
Nintendo invested in a price cut for the 3DS last year and they had losses because of that. But it served the purpose. What if the system was still at 249$?
So no the comparision is far from flawed. Commitment is the key in all the cases.