I used to agree with this and be against bots for similar reasons but after learning how the Rep system works and existence of closed voting groups and how difficult it is to begin on steemit i dont think this is too much of an issue currently or at least the cost is much to high to abuse successfully without significant investment.

And removing would would take something of great use to new users,
I dont think the comments do much good though and discourage engagement on posts.

A more important feature bots should have is restriction caps so they remain a tool for small new users and once thresholds are past either payouts are capped or stopped altogether especially with biding bots as new users couldn't hope to compete with any users making say $200 a week when they make $20.

Say for example to receive the same amount of Rep elevation from bots compared to say a $40 full vote from a 65 Rep user i think you would need to pay maybe 5/6 times that to receive from bots when a user could do for multiple others at no cost to themselves only to pull from system.

I do think Rep system needs a overhaul of sorts with something in place to discourage self voting too much and continuous up-votes between the same users in closed voting groups.

With each consecutive vote within certain time period Rep increase and value given to the same users also to self decreases and to restore would need to spread votes out around 3 times the weight with more restored for new and unique users to the time period, this would discourage closed voting groups and encourage curation of new/different users
for 30% of selfvoting within the time period to restore.

I think there is a need some for an easier method for fixing Rep both up and down maybe without effects on value because once users reach high enough or low enough it is not feasible and near impossible to fix.

About the people abusing voting system like this and with fixing being difficult shows problems with flagging system even without bots this can be and is done with closed voting groups and as the site grows will become an impossible task to even monitor.

I think there needs for some sort of incentive flagging system with maybe elects from witnesses given either rewarding or flagging capabilities to get encourage more users to actively flag there is plenty of a resource pool in terms of working humans here who make very little on posts which they could benefit them help steemit at the same time.