They've still lost 2 Super Bowls when they were overwhelming favorites. How many teams can say that.
I try to resist getting into a you-know-what kicking discussion about football and especially the Patriots, but this logic always shocks me. It's like saying (before Sunday) that Montana was the greater QB because he was 4-0 in superbowls while Brady was "just" 4-2. It's a completely bizarre reasoning that gets you there. It actually gives credit to Montana for failing to win as many conference championships as Brady has.
Fact is, that the superbowl is a single game, not best out of 7, where outlying crazy plays can get normalized over the space of multiple games. Stuff happens; heavily favored teams on any given Sunday get upset.
The trick is to give yourself as many opportunities over as many years to win as many one-off single games as possible. That's the only way to normalize against injuries, dumb ref calls, and balls bouncing in odd directions on any given Sunday.
The Patriots have been to 7 superbowls in 15 years. Given free agency, the salary cap, the Patriots always drafting at the bottom of the order, and (now I'm tipping my New England fan cap) an empty-suit commissioner who occasionally puts his hand on the table, what the Patriots have done, as Geno has said many times, is simply incredible.