That doesn’t mean it’s wrong. http://www.fallacyfiles.org/slipslop.html

Doesn’t mean it’s right either. Taken from the link you cited:

> One reason why I am skeptical has to do with the difficulty of the causal reasoning needed to establish that a slope really is slippery; most slippery slope arguments make little or no attempt to do this hard work. Moreover, it is difficult even in retrospect to tell whether a slippery slope mechanism has actually been at work.

I see no attempt on the part of the commenter I replied to, to make this kind of effort. And to save them the effort of doing so- even if they had established the presence of a slippery slope, they’d still need to prove it was the causal agent of the consequences they described.

Short of evidence to prove in advance that action A will lead to consequence B, this comes across as scaremongering.

The flaw here is talking about the 'rich'. You can divide rich into absentee landlords collecting hight rents and stifling the economy down and the actual rich who became so through entrepreneurship or other positive impact activities.