>  Voters of this article would have the same impact by upvoting someone who is powering up and selling their SBD

This is incorrect. Someone who powers up may (and nearly  always, in practice, will) power down and sell later. Secondarily, someone who is active on the platform and powers up is probably themselves upvoting content (possibly their own). Finally, in most cases when you upvote you have no assurance that the recipient will indeed power up, even if they have been doing so before. That has a very different impact on both the platform and the market compared with voting for something that has a commitment to: a) power up, b) not upvote using the resulting SP, and c) power down _and burn_ (not sell) later. 

The only  differences between burning immediately and powering up and burning later are: a) a temporary increase in the market cap of STEEM in the interim, b) the burn-pending SP can be used for important (arguably necessary) community-benefit purposes which have no other economic incentive nor obvious source of funding such as downvoting spam, and c) the burn-pending SP could be stolen if the operator goes bad or the account is hacked (and not recovered).

> There is no evidence that SBD will go back under $1 USD

There is actually considerable evidence, as it has dropped from about  $12 (occasionally momentarily higher, but $12 was at least briefly sustained) to a little over $2. While STEEM has also dropped, SBD has dropped a lot more, as is apparent from the internal market price of STEEM expressed in SBD (which has climbed from about 0.50 to 1.40).

This, of course, is not proof that SBD will decline to $1, and certainly no one can guarantee anything about future market prices, but it is evidence of a very strong and sustained trend in that direction. @burnpost is probably contributing in some modest way to this, but the degree is difficult to measure. (@burnpost has sold about $100K worth of SBD, but the impact on the market from constant ongoing selling pressure day after day is not necessarily a direct function of its amount.)

> and if [SBD does go below $1] burning large amounts of it would likely limit the supply and increase the price again

I don't see what that has to do with @burnpost at all. Destroying excess SBD when the price is below $1 is the normal mechanism for maintaining the peg and has always worked. It is only the upper bound peg (which this initiative supports) that doesn't work well on its own.

Also, if you don't want it on Trending you are free to vote for the "additional support" comment instead of the post, or indeed downvote the post. However, personally I see nothing preferable at all about the paid-vote posts ending up on Trending which are at least 90% of it. In no way would any sane person claim that Trending is a value-based assessment of the 'best' posts. It is just a snapshot indicator of posts where the money is going.