I'm concerned that removing the curve is going to invite back the high-volume low-value spam comments we've had in the past but mostly gave up since it became impossible to earn a reward with most low-HP votes.

But with the curve removed, you can, in an automated manner, spin out a very large number of comments all over the place at very low cost and if even 1% of users are fooled into thinking that your bot-posted "Great post!" is sincere or just reflexively want to reward "engagement" then you can make a profit.

Downvoting can work to counter this but it relies on already overworked and under- or un-compensated abuse fighters. Most people don't bother. The balance of effort and payoff very much favors the spammer.

I guess we can see how it works out and then reassess, but IMO removing it and replacing it with nothing is a mistake.