I absolutely disagree, it's extremely sustainable. You're an agent so I will defer to you and how you'd personally react. You know yourself that you can't get emotionally wrapped up in these transactions.
My "LOI" states that we are real estate investors and know the offer is low. Please email or call us back with any questions. We aren't trying to be insulting to your client or waste your time. We offer a very valuable service to sellers that want to close fast for cash or simply want to just get the house sold for any other reason.
Some will get upset, but surely you'd agree that as an agent, you can't control the monetary size of the offers submitted whether it's an investor or anyone else looking for a deal.
So would you get equally upset towards a first time home buyer looking for a deal?
I never said it's the most effective way to find deals, as there is no one "best way", I simply wanted to help any other investor that needed a cheap way to generate leads.