Sadly, I think they are really considering it.
As you mentioned, it will increase champ select times, and it will increase the chances of someone dodging, either because of it taking so long, or because the odds of their pick being banned.
I think the thing that people aren't considering however, is that it will increase the minimum champion pool required for newer players.
Currently with 6 bans you MUST have at least 16 champions owned.
With 10 bans, you will be required to own at least 20 champions.
There are currently only 13 450 IP champions
Of those, Garen can be picked up for free.
Tristanna and Alistar can also be received for free, so we're up to 15
That means you still have to get 5 more champions at 1350 IP
3 (free) + 12 (450) + 5 (1350) = 12150 IP
Oh, and that is assuming that at least a few of those champions are ones you are maining or at least comfortable playing.