Indeed. This letter is an attempt to justify and rationalise their actions. Essentially, it amounts to saying "we're sorry you were offended and felt hurt by our legitimate work but we had no choice but to lie to you and unethically experiment on you without your consent or we wouldn't have been able to do it". Their statement is not an actual apology, even if it is phrased in the language of apology, and it is an excellent example of what not to write if you are seeking forgiveness.
The core issue here is that the system under which they were working, and the researchers themselves, did not consider this work to amount to unethical human experimentation - even though the work directly involved infiltrating and exploiting humans and human social systems. There is no mention of this nor of any substantial desire to understand or address this systemic failing and, until there is an unconditional acceptance of responsibility for the harm caused and a real actionable change for the better with accountability, I don't see how we can consider this matter to have been apologised for.
The core issue here is that the system under which they were working, and the researchers themselves, did not consider this work to amount to unethical human experimentation - even though the work directly involved infiltrating and exploiting humans and human social systems. There is no mention of this nor of any substantial desire to understand or address this systemic failing and, until there is an unconditional acceptance of responsibility for the harm caused and a real actionable change for the better with accountability, I don't see how we can consider this matter to have been apologised for.