"Samuel Adams Boston Lager is not a beginner's beer."
And the first thought to flit across my mind in answer is, "The fuck it's not!"
I try to keep a certain appreciation for Sam Adams beer, and there are plenty of times when I've been grateful to find that at least they have Sam Adams, "they" being whichever bar/restaurant/store I happen to be purchasing in that doesn't have actual good beer.
Sam Adams and equally Newcastle Brown Ale were the beers that introduced me to a higher standard and were, for me, a stepping stone to a better appreciation of better beers. As I've come to drink better beer, I find that those beginner beers just don't reach the quality standard I've come to appreciate.
Furthermore, I must point out that I've come to dislike most lagers. Most big American beers are lagers, a style that, at its best, just doesn't stand up to the ales. So even at it's best Sam's Boston lager is nothing more than a really good version of the crappy beer I could have at half the price.
So, yes Mr. Jackass Sam Adam's Brewer, your best beer, your shining example, your pride and joy is a fucking beginner beer. You and your beer are lucky to be a stepping stone. You're like a halfway house between the insipid Bud's and Miller's of too many people, the welcome mat on the gateway to brewers who make really good beer.