Aloha!!!
I like a point of view a sharing!
I think that they did affect the viability of the platform because they increased the perception of Steemit from the outside as one big rigged stramash of a ponzi in which you had to hand over money to achieve anything.
Plus the fact that they werent really being used for promotion but in actuality were being used to buy cheap steem. Essentially, send me 1 steem and you will earn 1.2 back. The people that were the worst abusers of this were quite literally spending money on bots and constantly powering down to remove steem from the platform leaving only a little to pay for the next vote. It was kinda depressing to see.
Which brings me to number two.
I think that big stakeholders certainly didn't whilst there were easier ways to obtain their much vaunted ROI and that was to delegate all their stake to the bots. It was the easiest and surest way to get returns, however without the bots they will have to earn their returns somehow. Quite a few have turned their hands to curation and I think the rest will or follow a trail to do it which means that they will still be curating, in the third person sort of.
And on point 3 I know lots of people that left because once bid bots took a hold and the bigger stakes began delegating to them there weren't any rewards any more and it was demoralising and defeating to stay. We lost so many people over the last year or so it was depressing even for a chirpy chap like me.
All of the above I think were sending Steemit into a death spiral which is why I think such radical steps were/are having to be taken. Medicine don't always taste nice.
But this is only my humble opinion too.
Oops sorry!! I thought I had but I was rambling a bit toward the end.
I think free flags/downvotes are good for the simple point that people use them now, where in the past it was literally seen as a "waste" of voting power. As in you could reward yourself or others with real magic internet money or you could use that voting power combatting spam. Most people chose to reward. Now with free downvotes people can downvote without wasting their VP. I know that it is the main reason I have been throwing them around because I dont have to worry about my VP dipping too low anymore. There is potential for malicious use of them but I like to think that me and a lot of people I know use them pretty much on bid bot activity and genuine spam.