First off, no, brewing is not about competitions.
Yes, some homebrewers enjoy competitions, and some don't but that's really personal preference.
Just as what styles you choose to brew are your personal preferences. To each his own...so brewing is about many things.
Now, to the question asked in the poll:
You could pose the same question regarding many things that the AHA does. For example, does the AHA spend too much time and money on the forum? I'd say that by observing participation in the forum you could conclude that many members get enjoyment and utility out of the forum...therefore it is a worthwhile AHA activity. Ditto for how many members actively participate in competitions...some people must enjoy comps; you certainly see a lot of questions pop up on the forum in relation to them.
BTW...I voted "beouf," as I have no idea how much the AHA spends on competitions, or if entry fees cover everything, or if the BJCP competition registration fee covers the costs...so I lack the required information to make a sound judgement.
I'll just assume the following: for the percentage of members who enjoy and want competition related content/activities, a percentage of their AHA dues goes to help pay for any AHA competition related content/activities, and so no burden occurs to those who have no interest in competitions.
Just my own jacka$$ haole opinion, a Georgia cracker just south of the Palmetto state.