You maybe see the sells from someone who calls 
This guy owns a huge Bot network to farm Splinterlands Rewards. Sure it's decentral and he can do whatever he wants.
But, the network is not little at all. From a short ( not deep) explorer analytics, it should be around 10k wallets up to way more wallets farming rewards.
Should be a good business. The problem I see, reward cards were in the past well distributed ( reason for the good value around those cards), because of those farms it makes it difficult to invest in rewards cards IMO, to make money in the short run.
Wanna see what I mean?
https://peakmonsters.com/@fireking/explorer
Filter: Gift cards and you see it. Maybe someone is interested to look way deeper into it and makes some cool statistics about that.
Not sure it is a profitable business or not. Because the wallets are not for free, and free play players take forever to build their first deck with higher-level cards from daily rewards.
In general, I see no big problem with it at all, simply because cases like that improve in a longer-term the gameplay and find better ways to distribute rewards, also because of the selling pressure, it can be a good way to become cheaper cards.
It would come to a problem if those cards don't hit the market IMO. Then we would see a reward card monopoly that would damage the game.
Some thoughts about it;
Does it damage the game in economics?
I think for now no. The biggest difference is a single entity has control of those rewards cards. As long as those cards hit the market, there should be no long-term problem about this. It speeds up also the process of card printing.
Does it damage the image of Splinterlands?
I would say yes. Because I think there are more bot farms, it makes it really difficult to show the real users of that game.
Open Market
Does an Investor invest 100k USD into Cards, SPS or bots should make no difference.
1 Problem is the Spellbook sales don't benefit the secondary market at all. So the Value thrives from the secondary market into Spellbooks. Also, the 5% of sales fee doesn't benefit the holders.
So it is an indirect leech from Holders.
Another thing is the long-term impact. On a short scale, the effect is not that bad. It is like an Pack sellout to whales ( like the land sales).
The long term can become a problem.
Because play to earn = time and skill valuable. Bots don't care about time, so there must be needed more skill for the game.
To "protect" the game in a long run against bots, the game must simply become more complex.
Some FUD at the end, I have no proof about,
I think there are more Bots than real players for now. If this should not be the case now, it will come sooner or later.
It is IMO like online poker. If Bots/ computer programs become more effective than players, the game dies. With the difference, Splinterlands can make the game more complex in the favor of humans and change the parameters.
Like I mention earlier, I think that's not a big deal at all and should benefit the game in a long run.
And no, I'm not one of those Splinterlands Millinairs that wants to protect their value with "it's bullish" and "everything is fine" :)
I'm more of " i sold out my cards for pennys" :D
Btw,
How many other networks are out there? Would be interesting to become some insider Information about that.