Unfortuntely the people they target are the ones that just click through installers without actually understanding what it is telling them, the people that just want the software they thought they were installing and don't realise the consequences of all the bundled crap they get.
For me it's a predatory business practice little better than all the other spyware and malware that gets bundled except this uses some donations to charity to give it a veneer of respectability.
Using the following excuses shouldn't absolve the company of any responsibility either, it's their software and they pay for the distribution.
"They also said that they do not have the choice of what software they are bundled with."
"Charity Engine reported that they do not have control over how their software is bundled"
The fact their attempts to get people to activly download the software through more regular advertising and social media (which would require at least some engagement from the user) have failed, that 99% of the users come from these "bundles" and their user turnover is 6 months tell me that most people when they become informed of the consequences don't want to be involved.