i think there is no right and wrong answer to that, it's a matter of perspective. For instance i made an "oath" and many others too, not to spend a single $ of our own and only earn and spent what we are making here. So there is no way "people like me" to buy more Steem and thus SP.
Also, for me that mostly everyday making posts, upvoting, commenting and replying (all manually) if somebody gave me out of nowhere a certain amount of sp or add me in his autovoting list i would feel like he/she is giving me the world. Like my posts actually deserve something cause right now and given the real active users and bid bots there is not actual interaction and true content value. Thus i would get the motivation to become even better and even more active and thus spreading more Steemit, cause i would feel great
As i said again it's a matter of perspective and i think we are both correct and wrong at the same time. Some people with the extra sp will get motivated and and become way more active and others will just become more greedy especially if the delegation is for longer time